


Connections Made and Unmade

by Nix (CrimsonQuills)



Series: The New York Connection [10]
Category: CSI: NY, Numb3rs
Genre: Case Fic, Centaurs, Crossover, Dominance, M/M, Pre-Slash, Transformation
Language: English
Status: Completed
Published: 2011-11-16
Updated: 2011-11-16
Packaged: 2017-10-26 04:01:06
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 32,262
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/278461
Author URL: https://archiveofourown.org/users/CrimsonQuills/pseuds/Nix
Summary: <blockquote class="userstuff">
              <p>Don and Mac catch a break in the case.</p>
            </blockquote>





	Connections Made and Unmade

**Author's Note:**

  * Inspired by [Horses of Different Colors](https://archiveofourown.org/works/17898) by [james](https://archiveofourown.org/users/james/pseuds/james), [Wolfling](https://archiveofourown.org/users/Wolfling/pseuds/Wolfling). 



> hanks to Moonbeam for her awesome beta reading. My work always comes out better for your attention, Moon. Thanks also to James Walkswithwind and Wolfling, who allow me to play in their "Horses of Different Colors" universe. There would be no centaur!Don or centaur!Mac or centaur!Flack without you. :-)
> 
> DEDICATION: To all the fans who sat through the many progress reports and had faith that this story would be finished, even as the months stretched on. And to all the fans who saw that this series hadn't been updated in a year, but who took a chance on reading it anyway.
> 
> IMPORTANT TIMELINE and CONTINUITY NOTE: This story occurs a few weeks after the Numb3rs and CSI:New York season 2 finales. Because of the way this universe is developing and the time when I started writing this story, neither season three happened in this universe. I may pick and choose season three canon to use, later, but for now, we're operating with Season2!Don and Season2!Mac. Also, sharp-eyed fans will note that in this fic, Don's mother is named Carol, while in the show she's named Margaret. That's because TNYC 1 was written before she had a name, so I gave her one. I refuse to back edit my universe, so Carol she remains.

Don leaned back in his desk chair and hit the right arrow key on his keyboard, advancing to the next image. Yet more blood spatter. At least the spatter across the walls looked more like impressionist art and less like Rorschach blots. "I'm on inventory item 1196-24," he reported into the phone. "More spatter. And I thought you said that Flack still had two weeks of rehab left?"

"He does," Mac answered. "And he'll be doing it, but he convinced the chief of detectives that it was just strength-building and that he could build strength just as well on the job. That blood spatter's on the south wall, by the way. More cast off from the baseball bat. I spoke to the chief of detectives, but he didn't think much of my ability to evaluate Flack's readiness."

"What, didn't he think you were familiar enough with the injury?" Don asked, snorting. He contemplated the blood spatter, but really, it might as well have  _been_  impressionist art for all it told him. If Mac said it was cast off, it was cast off.

"I think my familiarity with the injury is the problem," Mac said dryly. "Apparently tying a man's insides together with a shoelace has a negative impact on objectivity. We done with this photo?"

"Yeah." Don glanced at the inventory and suppressed a sigh. Just twelve items to go. He advanced to the next picture. A lamp, this time. "Speaking of your adventures in first aid, how are  _you_  doing?"

There was an almost unnoticeable pause. "I've had a few restless nights," Mac said casually. "More or less what I expected."

"You talk to someone?" Don asked, ignoring the lamp for the moment.

"We're on item 1196-25, right?" Mac said. "The lamp?"

"Yes, we are, and I'm going to take that as a no," Don said, frowning. "I told you to talk to someone."

Mac sighed audibly. "I don't need to talk to someone, Don. Everything is fine. Every _one_  is fine. A couple of bad dreams do not necessitate a shrink. Besides, I'm talking to you."

As much as Don appreciated the sentiment, he knew that working through this kind of trauma was best done in person. Body language was a necessity when the person you were talking to was trying to avoid the topic. Briefly, he debated calling the NYPD shrinks and tipping them off himself, but only briefly. Pissing Mac off wouldn't do his peace of mind any good. "It's more than a couple of bad dreams," he said instead. "There are a lot of pretty intense memories tied up in those events."

"I've dealt with those sorts of memories before," Mac said. "I can deal with them again. Besides, Flack pulled through."

"Thanks to you." Idly, Don paged over to the next photo. A small table, spattered with blood, and a pile of mail, also spattered with blood.

"Yeah," Mac said, quietly.

Don's attention sharpened. "We talked about this."

"I know. But I keep coming back to the fact that the guy was almost obsessed with me."

"Which was  _his_  problem. You were doing your job and Flack was doing his. Nothing you did or didn't do was to blame for the explosion."

"I still feel responsible," Mac admitted.

"Because of Flack's tendency to follow your lead?" Don prompted.

"In a way, yeah." Mac's voice took on a wry tone. "And here I thought I left that sort of responsibility behind when I left the Marines."

Don snorted. "Responsible people never leave responsibility behind. There's too much of it to go around and not enough people willing and able to shoulder it."

"Which is how some people end up chasing unsolved murders from 1996," Mac said dryly.

"Do you mean you or me?" Don said, grinning.

"I think three victims makes this one enough for both of us."

"Assuming this really is a single case." Don paged ahead to another photo of blood spatter. "This is a hell of a lot of blood. Stefanos and Davies were killed in their home, in close contact with the perp. Esteban was killed from the other side of the country with an attack practically custom designed to avoid collateral damage."

"Just because the killer took advantage of Esteban's compromised immune system to use a weaker strain of anthrax doesn't mean that they wanted to avoid other casualties," Mac pointed out. "Maybe they couldn't get access to a stronger strain."

"Then why use anthrax at all?" Don argued. "I swear, the longer I think about this case, the less it makes sense. I can't figure out what a recent Greek immigrant, his long-term lover, and his INS investigator could do to motivate someone to go to such lengths to murder them all. Esteban's death was strange enough all on its own. Barely a dozen people even knew he'd inherited an immunodeficiency. Ten years ago I thought access to that knowledge and the anthrax would make the case easy to close." He snorted. "Shows what I knew."

"At least you were aware it was a strange case," Mac commented. "Up until you dug up the connection, the Stefanos/Davies murders gave every sign of being ordinary, complete with piles of evidence. Whoever caught the case must have been frustrated as hell by his inability to turn up any suspects considering the amount of fingerprints they left behind, not to mention the DNA."

"You've got to respect the victims that put up a fight," Don said.

Mac sighed. "I just wish we could have done more with the piece of their killer that they took with them."

"Hey, we haven't given up yet, right?" Don replied. He tapped the arrow key again and froze. "Mac?"

"Yeah?" Mac responded, his tone suddenly intent as he picked up on Don's change in focus.

"Item 1196-28. A letter." Don leaned forward, phone still pressed to his ear, and stared at the screen.

"I thought we were on 1196-25?" Mac sounded confused.

"Forget about the lamp," Don said impatiently. "Tell me about this letter."

There was the brief sound of keys clattering before Mac answered. "It's blood evidence. It was on the top of a pile of mail on the hall table. Some spatter got on it, so it was logged. Why?"

Holding his breath, Don magnified the postmark once, then again. And again. It was blurry, but he could read it. "Because I think we just found the connection between our cases."

" _What?_ "

Don started to grin. "I recognize the handwriting. I'm no expert, but I stared at the envelope that killed Carlos Esteban on and off for ten years and I'm telling you, the same person who addressed that letter addressed this one. I just checked the postmark--it's the same as the first postmark on Esteban's, from before it was forwarded."

"Damn," Mac said, his tone stunned rather than displeased. "Don, you do realize that this letter is addressed to Robert Davies, right? Not Evander Stefanos."

"Yeah, I know," Don said, grinning broadly now. "Which means this case just got even stranger. But you know what? I don't care. I just hope you don't catch any hot cases in the next couple of days."

"Why?" Mac asked, but the sly tone to his voice told Don he had an idea already.

The smile was starting to make Don's cheeks ache. "Because your lab is about to rack up some hours on a cold one in the name of interagency cooperation. Carlos Esteban was a Federal Agent and this is new evidence. The Bureau will cough up a plane ticket and a couple of days for that even if it is ten years old. I'm coming to New York."

***

Don stared down at the case file that lay open on his tray table and tried not to think about the fact that he was 30,000 feet in the air and nearly an hour away from getting all four hooves firmly on the ground. Or at least both feet, but right now he desperately wanted to be as solidly planted as possible and he'd be a lot more connected to the ground in centaur shape.

It was no good. He knew this case backwards and forwards and inside out, far too well for it to be even mildly distracting. Don flipped the folder shut and took a shaky breath, leaning back in his seat and reminding himself not to close his eyes. He wanted to, but he knew from prior experience that trying to block out the sight of the plane would only emphasize the gut-level awareness that the ground was  _not_  under his feet.

"Are you okay?"

Don turned and gave his seatmate a weak smile, carefully not glancing past her at the open window shade. "I'm fine," he said. "I just don't like flying much."

Her expression softened into sympathetic lines. "If it's any consolation, you've been doing really well."

It wasn't, but she was only being polite. "Thanks."

"So why are you headed to New York?" She'd put her book back into her purse, apparently settling in for a conversation.

Don debated politely putting her off, but...well, it was worth trying out an alternate distraction, at least. "I'm an FBI agent," he said. "I got a lead on a cold case that I need to check out."

Her eyes had gone wide. "Seriously?"

Don smiled a little. "Seriously," he assured her.

"Wow. Usually it's just a vacation or visiting family or a conference or something," she said. Her eyes took on a sparkle. "So do you get back up in New York, or are you on your own?"

Scenes from endless manhunt and murder mystery movies were doubtless flashing before her eyes, the lone hero fighting for the truth against blind, faithless, rule-bound superiors. Don smiled and shook his head. "I've been consulting with the head of the NYPD crime lab for nearly eight months. Between the two of us, I doubt we'll have trouble rounding up help if we need it."

"Oh," Don's seatmate said, visibly disappointed. "Well, catching the bad guy is the important part, right?"

"Right," Don agreed, amused. Although, to be honest, he was looking forward to meeting Mac just as much as he was anticipating closing the case. If someone had asked him eight months ago whether or not it was possible to really be friends with someone you'd never met in person, Don had to admit he would have said no. Maybe it was a bit old fashioned, or maybe it was the centaur in him that placed more weight on instinct and scent than humans did, but he'd honestly believed that you had to connect on that visceral level to really be  _friends_  and not just friendly acquaintances.

But Mac...Mac had a way of picking up on what he was saying, of following Don's thoughts that Don had never encountered before. It was like he had some inside information, a cheat sheet for Don's attitudes. Even more than that, it seemed to go in both directions. If they could do that with nothing but each other's voices for cues, what could they do with all the wealth of body language and--for Don, anyway--scent to draw on?

 _You'll find out soon enough,_  Don reminded himself. Mac had volunteered to pick him up at the airport and ferry him to the lab. It was probably a minor waste of time--Don  _could_  just take a cab and let Mac use the time to begin processing the envelope--but it hadn't even occurred to him to turn down the offer.

Don checked his watch. Forty minutes. Unconsciously, he started bouncing one leg impatiently.

***

Don breathed a sigh of relief as he stepped off the jet-way and into the much more solid terminal. It'd be even better to get out on the street, but this was good enough for now. Settling his briefcase in one hand, Don pulled up the handle on his wheeled carry-on and headed through the terminal to the luggage carousel. He hadn't checked anything, not for a three day visit, but it had been the easiest place to arrange to meet Mac.

As he wove his way through the crowds of arriving passengers and approached the carousel, Don caught a faint whiff of something that made the hair on the back of his neck stand on end. Brow wrinkling, Don slowed to a stop and took a deeper breath. Shit. There was another stallion somewhere in here. Between the excess of humans, all of them smelling slightly sour after hours cooped up in planes, and the air conditioning, he couldn't quite tell where, but he was definitely somewhere in the arrivals area.

 _You got permission to visit from the nearest herd stallion,_  Don reminded himself,  _and you're not looking for trouble. Just find Mac and get out of here._

But the scent only got stronger as he approached the carousel that was displaying his flight's information on its digital read out. Don couldn't help the tension that crept into his muscles or the way his eyes started scanning the crowd, looking for the threat.

Instead of the other stallion, Don found Mac, standing to one side of the carousel, out of the way of the crowd that was jostling for a good position from which to grab their bags. He looked almost exactly the same as he did in his file photo, right down to the expression: serious and intent. Mac hadn't seen him yet, so Don took a calming breath.  _You'll be out of here in a couple of minutes._

Mac's eyes finally swept across the crowd and met Don's gaze. Don summoned a smile--genuine, if a little more strained than he would have liked, thanks to the awareness of another stallion that rasped across his sense--and headed for Mac.

A few steps away, Don's heart slowly began to sink even as his back straightened and his smile slipped. He was getting closer to the source of that scent, not further away. The only person he was getting steadily closer to was Mac.  _It could still be someone else,_  Don thought despairingly, but...he could see a matching awareness growing in Mac's eyes.

By the time Don came to a halt in front of Mac, neither of them were smiling anymore. Don's neck and shoulders already ached with tension and there was a knot in his stomach that was only made worse by bitter disappointment.  _Eight months and three thousand miles,_  he thought,  _and now you're going to have to go find a quiet spot and do your best to batter the man into submission._  It didn't matter which one of them won; either way, the easy camaraderie they'd developed over the phone would be broken, probably permanently.

The two of them stared at each other for a long time. Finally Don let go of the handle of his carry-on, put down his briefcase, and set his jaw. "If we're going to work together for the next three days," he said tightly, "we'll have to go somewhere and settle this."

It was even worse to say that than he thought it would be.

Mac held his gaze for a long moment and then, strangely, his shoulders relaxed and his lips curved up into a slight smile. "That won't be necessary, Special Agent Eppes," he said quietly. "The NYPD CSU is at your service."

For a moment, Don wasn't sure he'd heard right. Mac slipped his hands into his pockets and waited, head tilted to one side, and slowly it sank in that he really had let go of the confrontational air. The visceral awareness of another stallion still danced across Don's nerves, but it was settling into a low hum instead of a near-painful rasp.

"For the next three days?" Don asked cautiously.

Mac hesitated, his smile fading. "If that's what you'd prefer," he said, "but...I've been pretty much at your service for eight months now."

Don broke into a smile and ducked his head in a brief laugh. "I suppose you have been," he said warmly. He held out his hand. "I'm glad to finally meet you in person, Mac. Even if it didn't go quite the way I imagined."

Mac took Don's hand in a firm grip and shook it briefly. "Likewise," he said. He scooped up Don's briefcase and nodded towards the parking structure, falling into step next to Don as they left the terminal. "Although I confess, I'm more than a little confused now."

"By what?" Don asked, curious.

Directing Don toward his car with nods of his head and the occasional pointing finger, Mac answered with a wry smile. "By your family. I wondered more than once if you and your family were aware of us, but between the fact that you have a father and a brother that you spend considerable time with and the fact that you share their family name--which isn't the name used by the local herd--it never occurred to me that you were one of us yourself."

"That confusion I can't fault you for," Don said, laughing a little. "I have an odd family history, even for one of us." He paused and waited for the inquiring eyebrow, a little detail of body language he'd been imagining for months. When he got it he smiled, then suddenly looked around at the surrounding cars and fellow travelers. "I better save the rest for the car."

"It's not far," Mac said. They took an elevator up a couple of levels in comfortable silence and got Don's luggage stowed in the trunk.

"So, my unusual family history," Don began as he belted himself into the passenger seat. "When I was nine years old a new stallion took over the herd. He was young and a little insecure, and he fostered out all the colts ten and over immediately."

"I thought you said you were nine?" Mac glanced at Don, but quickly returned his attention to the twists and turns that took them out of the parking area.

"I was," Don grinned. "I was also pretty aggressive. He made an exception."

Mac paused for a moment. "You don't seem exceptionally aggressive to me," he said, slightly diffidently.

"That's what being raised as much by a human couple as by other centaurs will do for you," Don said, smiling to let Mac know he hadn't taken the comment as a critique. The little gesture of reassurance came to him with a surprising lack of forethought. For all his years of discreetly taking care of Charlie, his dad, and his team, Don had never had dominion over another centaur. Hell, it had been twenty-seven years since he'd even been able to play dominance _games_ ; he had to be on his best behavior on the rare occasions he visited the herd. Even this brief exchange--Mac testing the boundaries, Don letting him know it was safe to push--made Don's stomach churn with a combination of nervousness and anticipation.

"Anyway," Don continued, "imagine me, nine years old and just coming into my instincts, suddenly tossed out of the herd."

"And probably proud as hell that you could make the new herd stallion nervous," Mac said dryly.

Don laughed. "Yeah, I was. But I was also shaken up. I thought I had two or three more years to sort things out with the other colts before it was time to go it alone, you know? So there I am, and there are Alan and Carol Eppes, who realize not two months after they take me in that their three year old son Charlie is going to need a lot more from them than they ever expected." Don paused for a moment, remembering the scent of worry, the only partially concealed tension, and the late night discussions when they thought he was sleeping. "They needed me to be strong and independent and to help out with Charlie."

"Herd stallion at nine years old," Mac commented.

"Yeah. Even if they didn't know it." Don smiled a little. "A year after I was fostered out of the herd, I asked mom and dad to adopt me officially."

"Bet they were surprised."

"A little," Don admitted. As far as he knew, no other colt had ever been adopted by their foster family. But then, usually they went into their foster homes knowing it was just a short transitional period, a kind of halfway house on their way to independence. "I let them think that I wanted to belong somewhere. They understood that the way they wouldn't have understood that, as far as I was concerned, they belonged to me--a ten year old colt."

Mac glanced away from the road curiously. "Do they know how things stand now?"

"To be honest, I think they sometimes forget that I'm not human," Don said sheepishly. "They're familiar with centaurs; they'd know how it works for me if they took a minute to think about it. But they don't." He shrugged.

"I could only wish my people were as oblivious," Mac said, returning his attention to the road.

Don's shoulders tightened a little at the phrase 'my people.' He took a discreet breath and forced himself to relax. Whether it was a habit or a convenient way of referring to the team that he led, Mac deserved a couple of days to get used to the fact that he belonged to Don now. Get used to it, or decide that they needed to settle things a little more...traditionally. Don could only hope that it would be the former and behave accordingly. "I take it they know about you," Don said aloud.

Mac glanced at Don briefly, a wrinkle between his eyes telling Don that he'd caught the edge Don hadn't quite been able to keep out of his voice. "Just Stella and Flack."

Flack.  _He has an...inclination to follow my lead at times when you'd normally expect the detective to be controlling the case,_  Mac had said.  _Oh, shit._  "Flack is a stallion, isn't he?"

"Yes, but he--" Mac broke off and took a quick look at Don. "Oh."

"Tell me about him."

"He's a native of the area," Mac said, which told Don that Mac and Flack weren't related, since Mac was from Chicago originally. "Younger than me by almost fifteen years."

"Younger?" Don broke in, surprised. "Was it experience or training that tipped the balance when you fought?"

"Neither. I was...avoiding settling it," Mac admitted. "He just walked up to me and told me that as far as he was concerned, I was dominant."

Don's eyebrows rose. "That where you got the idea?"

"Yeah." Mac cast Don another brief look. "It didn't even occur to me that he could be a problem. I should have--"

"Mac," Don interrupted, "relax." Mac's jaw didn't ease out of its tight line. " _Relax,_ " Don repeated, more firmly. "It's not your problem."

Slowly, Mac let out a breath. "This is going to take a little getting used to."

Don hesitated, then reached out and laid his hand on Mac's shoulder, almost touching the base of his neck. "I'm not expecting you to give up leadership of your lab," he said quietly. "I don't expect--or need--total control of your life. I just want you to relax, to come to me when something's weighing you down instead of bottling it up."

"You mean like I've been doing for months now?" Mac asked wryly.

Don chuckled. "Yeah, just like that." He gave Mac's shoulder a squeeze and drew his hand back, turning in his seat a little so that he could watch Mac as he drove. Finding out Don was a centaur might have confused Mac, but discovering Mac was a stallion explained a hell of a lot of things to Don: the need to belong that had prompted him to join the Marines, his confusion over why he'd been so unsettled by the threesome he'd run into on that murder case, his atypical comments on love and independence that dove-tailed so well with Don's own, the perfect recall...

Mac glanced away from the road for a moment and met Don's eyes. "What?"

"I should have guessed about you," Don said. "Everything fits. It just never occurred to me."

"Given the small percentage the population that consists of lone stallions, there's no reason you should have," Mac said reasonably.

Don grinned. "I defy the odds, Mac. This is the second time I've come to New York and run into another stallion. And he was a sniper for the Marines, too. Was there a checklist I missed when I left the herd early?"

Mac laughed. "Depends. Did Gibbs become a cop after?"

Of course Mac would remember him mentioning Gibbs, even if it had been months ago that the man had come up in conversation the first time. "Close," Don said. "Naval Criminal Investigative Service. We met at a conference. Both being representatives of Federal agencies, we ended up on several panels together."

"I'm guessing neither one of you volunteered to back down," Mac said dryly.

Don wasn't about to undermine his authority with Mac. "We fought," he confirmed. But he wasn't about to lie to the man either. "But we got interrupted. Are we headed for the lab or my hotel?"

Mac shot him a curious look, but accepted the change in subject without question. "The lab. Given your time limit, I thought you'd want to get started immediately."

"You thought right," Don said with satisfaction. "I'll also need current addresses and phone numbers for all of the witnesses that were originally interviewed when Davies and Stefanos were murdered, plus their relatives and any close friends."

Mac nodded. "Check the back seat." Don raised his eyebrows, but twisted around and found a file box full of folders resting on the seat behind Mac. Don awkwardly wrestled it into his lap and rifled through the folders, finding everything that he'd asked for already there. He shot Mac an inquiring look, and Mac shrugged. "I had to do something while I was waiting for you to get here, and I figured you'd want to look at the envelope yourself before I took it apart to analyze it."

"Workaholic," Don teased even as he pulled one of the folders out of the box and flipped it open.

"You going to try to tell me you didn't reread that file again on the flight here?"

"Oh, I tried," Don said, grimacing a little at the memory. "It's a little hard to concentrate when you're thirty thousand feet above the ground."

"In the Marines, I was always about ready to kiss the ground when our transport landed," Mac said. "I think I got a reputation for being gung ho about missions, the way I was always the first one to get the hell out of the damn thing when we landed."

Don laughed a little. "And yet you live and work in Manhattan, home of the skyscraper," he teased.

The glance Mac shot Don acknowledged the irony with a small smile. "I'm not about to let what I am limit my life."

 _Limit his life?_  Don thought, a little startled. He'd always felt that being a centaur had added facets to his life--almost too many facets--rather than taking them away. He studied Mac for a moment, inhaling subtly to take in his scent. The aggressive edge that had put Don on guard at the airport had already faded completely. Now Mac just smelled...actually, he smelled pretty good. He didn't quite have the scent of a centaur who'd accepted their stallion-- _not yet anyway_ \--but there was something there that was missing from everyone else Don considered a part of his herd.

 _Of course he does,_  Don thought, amused at his own musings.  _He's a centaur. They're not._

He took another subtle breath. It was going to be an interesting three days.

***

Mac had to exert a conscious effort to keep his attention on driving. Don was a centaur. A _centaur._  Mac felt like he should still be reeling at the revelation, but instead he found himself settling into the conversation easily. The wariness and despair he'd felt when he'd realized what Don was had vanished as if they had never been, leaving him feeling oddly hollowed out and, inexplicably, faintly anxious.

The anxiety really didn't make any sense. There was no impending battle; Mac silently thanked Flack for his moment of inspiration. Nor was he worried about how Don would handle the authority Mac had just handed him. He'd learned enough in eight months of conversation to be comfortable with that.

But there was still a niggling sense of uncertainty in his gut. Mac did his best to bury it. He and Don had more important things to concentrate on.

Mac pulled into the lab's parking lot and waited a moment for Don to return the file he'd been reviewing to the box Mac had assembled. When Don had finished the page he was reading and closed the file, Mac nodded at it and the box. "You want to stash that in my office while we process the letter?"

Don looked up from putting the file away. "As long as you don't mind me hovering over your shoulder while you work," he said, smiling.

"I think after eight months, you've earned the right to be present at the great unveiling," Mac said, the corner of his mouth curving upward.

"If there is a great unveiling," Don said, opening the car door and holding onto the box as he slid off of the seat. Mac exited his side of the car, meeting Don's gaze again across the hood. "The fact that the envelope was addressed to Davies, not Stefanos, threw us something of a curveball. We gained the handwriting connection but lost the INS connection, and we have even fewer theories that could explain Robert Davies as an intended target than we did for Stefanos. I don't know what I'm going to tell my boss if we open this thing up and it's a letter from his mom."

"That depends," Mac said, falling into step at Don's side as they headed into the lab.

"On?" Don asked, raising his eyebrows.

"On whether or not his mother wanted him dead," Mac said, carefully controlling his expression.

Don broke into a laugh, his head tilting back and his eyes almost disappearing into a sea of crinkles. Mac could feel his own deadpan expression break into a smile. He couldn't help it. The way Don's laugh lit up his face was infectious.

"Well, it wouldn't be the first time," Don said wryly.

"Unfortunately not," Mac agreed as he showed Don into the elevator. "It's depressing how often the ones who hurt us the worst are those who are supposed to love us."

"Yeah," Don said softly. "I wonder sometimes if  _our_  instincts make us more or less susceptible to that sort of thing."

"As much as I'd like to believe a...leader's possessive nature makes him more likely to take good care of what's his, I know he's chosen by strength of body and mind, not strength of character," Mac replied, choosing his words carefully for all that they were alone in the elevator.

Don shot him a sidelong glance. "Speaking from personal experience?"

The elevator doors slid open and Mac stepped out onto his floor. "No," he said, shaking his head. "Ours was neglectful, not cruel." Mac paused with his hand on the door to his office and frowned thoughtfully. "Actually, to be perfectly fair, it was the boys he ignored," Mac amended. "As long as we weren't a threat, he didn't see why he should worry about kids that were only going to leave." Mac pulled the door open and let Don step inside ahead of him.

"That doesn't mean that he shouldn't--" Don stopped in his tracks just a few steps into Mac's office. Mac followed and stepped around him to see what had captured his attention.

The many boxes of evidence for the Stefanos/Davies case were still stacked up, six high and two deep, next to his desk. "Ah," Mac said, unaccountably embarrassed. It's not like Don didn't know exactly how much evidence they'd been through.

Don turned and caught his gaze, smiling slightly. "No wonder it took us eight months to go through it all."

Mac chuckled and rubbed at the back of his neck briefly. "You should have seen the expression on Stella's face when she saw it all," he said. "She asked if you were attractive." At Don's raised eyebrows, Mac clarified, "She was hoping I was doing you a favor because I was interested in a date."

"Does this mean I owe you dinner?" Don asked, eyes twinkling.

Mac felt a little flush of warmth and hoped he wasn't blushing. "No," he said aloud, "but that doesn't mean I'd turn it down, either."

Don just smiled and lifted the box of files he was holding. "You mind if I set these on your desk?"

Mac shook his head. "Go ahead."

Don set the box down and paused in the midst of turning away from the desk. He reached out and touched the files lined up along the edge with a gentle finger. He looked up and caught Mac's gaze. The teasing light had gone from Don's eyes, leaving them a subdued brown, edged about with sadness, as if that was the natural state to which they always returned. Mac waited for him to make some comment, but Don just nodded slightly, as if in acknowledgment, before stepping away from the desk. "So where are the labs?" he asked briskly.

"Just down the hall," Mac said, stepping back to let Don exit the room first. "We'll be working in the quarantine area," he went on.

"If this is the same strain as the one that killed Carlos Esteban, it's really not that virulent," Don commented. "Esteban was immunocompromised when he was exposed. Face masks are all that's necessary."

He was right, but Mac just shrugged. "We have the quarantine facility. No reason not to use it."

"You sure you don't just want to play with the high tech goodies?" Don teased.

Mac remembered going on at length about a few of the lab's new innovations to Don, but had to snort at the suggestion. "The quarantine room doesn't qualify as high tech," he said dryly.

"You're keeping all the fun for yourself," Don accused lightly, startling a short laugh out of Mac.

They arrived at the quarantine lab before he could respond and found Stella waiting for them. Mac suppressed a frown. "Stella Bonasera, Don Eppes," he introduced politely.

Stella smiled broadly as she shook hands with Don. "L.A.," she said appreciatively.

"They do that here, too?" Don asked Mac, glancing at him as he let go of Stella's hand.

"I haven't heard it before now," Mac said, leveling a look at Stella. She just kept smiling and tilted her head slightly towards Don, mouthing 'not bad' while Don was looking at Mac. Mac's look sharpened into a glare.

"I take it your own team has...taken note of the extended phone conversations," Stella said, turning her smile on Don.

"Every time I get off the phone they ask, 'Was that New York?'," Don commented wryly.

"We should probably get going," Mac said.

"I'm only here for three days." There was a note of apology in Don's voice, but it was also firm.

"Just a second," Stella said. She turned down the corridor and, not quite yelling, called out, "He's here!"

Firm never had had much of an effect on Stella.

Danny appeared out of one of the labs and approached at a good clip. Mac sighed and resisted the urge to rub at his temple. He hated it when his life was put on display. "Danny Messer, Don Eppes," he said when Danny got close enough.

"Nice to meetcha," Danny said, shaking hands with Don briskly. He gave Don a frank visual appraisal. Mac watched with interest as Don's spine straightened subtly and his shoulders came back a little in response. Mac's stomach tightened and the back of his neck prickled, but that was all.

"Do I pass muster, Detective Messer?" Don asked. His tone of voice was light, but there was an expression in his eyes that reminded Mac that this man was both a stallion and a senior federal agent.

Danny started to answer and then seemed to register Don's expression. "Not my muster you have to pass," he said casually.

Don didn't even glance at Mac, which had to have been was Danny was expecting, because he shot Mac a slightly confused look. Mac started to shake his head a little, then, sharply aware of the tension in Don's body, stopped.

After a moment, Don relaxed marginally. "I think Mac and I have each other's measure," he said, only now shooting Mac a quick glance. Mac tilted his head slightly in affirmation and Don looked back at Stella and Danny. "I appreciate the introductions, but we really should be getting started."

"I'm going to be pretty tied up with Don for the next three days," Mac commented as he keyed in the code to the door of the quarantine lab. "You can keep me posted by e-mail and I'll have my cell with me, but I'd prefer not to be interrupted unless it's an emergency. Any departmental decisions can go to Stella."

"No problem," Danny said.

"Good luck on the case," Stella added.

Mac gave her a short smile. "Thanks." He waited for them to take a few steps away before he pulled open the outer door to the quarantine lab and gestured for Don to precede him inside. They paused between the inner and outer doors to put on full face masks and latex gloves before opening the inner door with a soft huff of air.

The letter was waiting for them on the bench within. An array of tools were arranged around it. "The outside of the envelope has already been thoroughly photographed," Mac said as he attached a pair of clips to the corners of the letter, "so I'm skipping that step. I'm skipping the ALS, too."

"ALS?" Don asked.

"Alternate light source," Mac clarified. He carried the letter over to a small, empty tank and used the clips to suspend the letter from a string within. "It reveals traces of blood, even if the perpetrator tried to remove it. Our blood evidence is obvious." Don nodded, so Mac went on. "On the other hand, the envelope has never been fingerprinted before."

"What's that?" Don asked curiously as Mac dripped a little superglue into a tiny ceramic dish and set it and a small cup of water inside the tank.

"Superglue," Mac said, smiling even though the face mask hid most of it. "The fumes from heated superglue react with moisture in the air and the residue of fingerprints, rendering them visible."

"Cool," Don said absently as he watched the tank.

Mac smiled to himself and watched the fumes rise slowly from the little puddle of crazy glue to envelop the letter. After several minutes he sighed a little when no fresh prints appeared. "Unfortunately, there have to be prints present for it to work," he said. Opening the tank, he waited a moment for the fumes to clear before reaching in and removing the letter.

"Which means on to the next step."

Mac nodded and turned the letter face down on the lab bench. He picked up a scalpel and then paused and turned the handle towards Don. "Want to do the honors?"

Don started to reach out, but hesitated. "You're certain I won't be compromising the chain of evidence or something like that?"

Mac shook his head. "I'm sure."

"All right, then." Don's gloved fingers closed around the scalpel. After he'd settled it in his grip he considered the envelope for a moment before circling the table to stand on the same side as Mac.

More than just the same side. Mac hadn't moved away from the letter; to stand square with it Don had to step up close to him, their shoulders and upper arms pressed together. It was difficult not to be distracted by the swath of warmth as Mac leaned over the lab bench and spoke. "Just like with a letter opener. Insert the blade at the corner and slice along the seam."

Don leaned over the letter, pinned it down with one gloved hand, and slowly drew the scalpel through the top of the envelope with the other. The cut was made slowly but smoothly and Mac nodded in satisfaction. Don turned his head and grinned at Mac. He pushed the opened envelope towards Mac's fingers. "If there's anthrax in there, you should probably take the actual letter out."

Accepting the letter, Mac drew three shallow plastic trays across the bench. He lifted the letter over the first before carefully withdrawing a Z-folded slip of paper from inside. A small cloud of white powder emerged within it and slowly settled into the tray. Mac unfolded the paper and gave it a gentle shake, dislodging more powder into the tray. He set the unfolded letter down in the second tray. Tapping the envelope over the first tray released another shower of powder and the envelope itself went into the third tray.

Mac and Don leaned over the letter together.

 _Davies,_

 __

 _You shouldn't poke your nose into places it isn't wanted. You might snort something that doesn't agree with you._

 _No one but you gives a shit. Next year even the big wigs won't care what happened this year._

 _The Ones You're Looking For._

The two centaurs were silent for a moment.

"I'm guessing that's not what Esteban's letter said," Mac finally commented dryly.

Don shook his head. "It was blank."

Mac picked up the envelope and studied both pieces of paper. "I think we can safely say Robert Davies was the primary target. Which mean's Esteban's connection to Evander Stefanos was sheer coincidence."

"Yeah," Don said shaking his head in disbelief. "But we can discuss this outside. I'd like to get out of this mask sooner rather than later."

"Right." Mac picked up a camera laid out on the bench with the rest of the tools and carefully photographed the front and back of the letter. While Don watched he repeated the process he'd used to fingerprint the envelope, but briskly this time, since he wasn't introducing the process. He smiled in satisfaction when multiple prints appeared on the letter, but without much triumph. They'd always had prints, there just hadn't been any suspects to match them to.

Nevertheless, he carefully lifted each of the prints before going over the paper with ALS. As he'd expected, nothing new appeared. Both pieces of paper were sealed into new evidence bags. Mac finished up by scraping half the anthrax into an evidence envelope and the other half into a vial, which he carefully stoppered.

Holding the vial, he nodded at the rest of the evidence. "We can leave this here, in case it needs further processing. This," he held up the vial, "we'll take to DNA to match to the sample from Esteban's murder."

"You can do that?" Don asked, surprise clear in his voice.

Mac headed for the door as he spoke. "Anthrax is a strain of bacteria and bacteria have DNA just like people do. The only difference is that theirs is stored in the cytoplasm, instead of in the cell nucleus."

"I'll take that as a yes," Don said wryly. He pulled the inner door of the quarantine room shut firmly and the two of them stripped off their gloves and tossed them into a special disposal bin. The facemasks they removed and hung up again.

"It is a yes," Mac confirmed as they left the quarantine room. "Although we don't do it very often. There are usually easier, more conventional ways to connect cases."

"Appropriate that we need it for this one, then," Don said, snorting. "Nothing about this case has been easy or conventional." He paused and then suddenly cursed under his breath.

Mac frowned. "What is it?"

Don sighed. "I just realized: Esteban died in 1996. DNA profiling was still pretty new at the time. It would never have occurred to them to profile the anthrax, and I know for a fact that there is no DNA profile in the Esteban case file for us to compare with." He fished his cell phone out of his pocket and hit the first speed dial setting, raising it to his ear. "I'll see if David can bully our techs into running it quickly, but no guarantees."

Don quickly filled David--Mac presumed he meant David Sinclair, the agent to whom he'd spoken briefly when Don had been hospitalized--in on the situation. He thanked the other agent and flipped his cell phone shut just as they arrived at the DNA lab.

Stepping into the lab's doorway, Mac suppressed another sigh. Lindsay and Hawkes were inside, speaking with the DNA tech on duty. If Mac didn't know better, he'd have suspected they'd planted themselves there just to intercept Don. But there was no way they could have known when he and Don would finish processing the letter or where they'd go when they finished.

Lindsay and Hawkes turned to meet them as they approached. Mac exchanged quick glances of greeting with them before Lindsay turned to Don and held out her hand. "Lindsay Monroe," she introduced herself. "And you must be Special Agent Eppes."

"I take it Danny stopped by," Mac said dryly.

Hawkes flashed him a grin. "Just for a minute." He took his turn greeting Don, friendly but less blatantly curious, for which Mac found himself feeling vaguely grateful.

"If by 'a minute,' you mean more like ten," Lindsay added.

Mac did frown then. "Danny needs to learn a little more respect for people's privacy."

"Don't go too hard on him," Lindsay appealed. "He's just curious. He's worked with you longer than anyone but Stella and still he's never met any of your friends. You should have seen how fascinated he was when he found out you play the guitar."

"I keep my professional and personal lives separate for a reason, Lindsay," Mac said, a little stiffly. He'd seen the two of them in the audience at the club one evening, but he'd never mentioned it and he'd expected them to do the same.

"What about Stella?" Lindsay asked, raising her eyebrows.

Mac hesitated and Don cut into the pause neatly. "Sorry to interrupt," he said, not sounding the least bit apologetic, "but we do need to speak with..." he trailed off and glanced at the tech, inviting an introduction this time.

"Tom Masters," the tech responded.

"...Tom," Don finished, nodding his thanks.

"Oh! Sure, no problem," Lindsay said, slightly flustered. "Nice to meet you Agent Eppes." Hawkes nodded his goodbye and the two of them left the lab.

"I promise that's the last of them," Mac said when they were gone.

Don smiled. "I don't mind so much," he assured Mac. "I'd almost forgotten what it was like to be a person of interest after working with Charlie so much."

"Charlie? Charlie Eppes?" Tom asked with naked interest. When Mac and Don exchanged a glance, Tom's expression suddenly grew sheepish. "I read a report about a geographic profiling technique he developed and the elimination of suspects by found DNA samples," the tech explained.

Don nodded. "That was the first case where Charlie helped us in an area outside of the accounting side of things. The suspect wasn't actually found within the area Charlie originally profiled, but only because he'd moved recently."

"Not finding the suspect in his old neighborhood actually led to further validation of the technique," Tom said. "It forced Dr. Eppes to do an alternate profile based on professional habits instead of personal habits, and that profile led you to the guy's restaurant, right?"

"Right." Don looked over Mac, "Thanks to my dad," he said, smiling a little. "He was the one who suggested that everyone develops their habits in two different places, work and home."

Mac thought of how often Don had commented on the way his father worried about his work habits and found himself smiling. "But not in quite those words, I bet."

Don chuckled. "No."

A pause emerged in the conversation and Tom suddenly seemed to recall himself. "You said you came to talk to me. Something to process, I'm guessing?" He held out his hand expectantly.

Mac lifted the vial but didn't hand it over. "Take precautions when processing this, Tom," he warned. "We're expecting it to be anthrax and if it's the strain we think it is, it's already killed one person."

Tom's eyes widened a little. "Understood."

"When you've got a profile, get in touch with this guy in L.A.," Don said. He leaned over to scrawl on a scrap of paper on Tom's desk. "They've got a second sample there that we need to compare with."

Tom accepted the note with one hand and the vial with the other. "Anything else?"

"Put a rush on that," Mac instructed. He shrugged to indicate helplessness. "We're short on time."

"Sure thing," Tom replied, though he glanced ruefully at the stack of evidence waiting on his attention.

Mac nodded his thanks and turned to lead Don out of the lab. They paused in the hallway. "The break room or my office?" Mac asked.

"Which one has coffee?"

"Break room, then," Mac said wryly, and headed down the hall again, away from the labs and towards his office. "As long as you're aware that chances are good someone else will drop in there at some point."

Don slipped his hands into his pockets and shrugged. "Like I said, I don't really mind."

Mac shot him a curious glance. "Why do you keep interrupting them if they aren't bothering you?"

The look Don gave him told Mac that the answer should have been obvious. "Because it bothers you," Don said simply.

Mac frowned and slowed his steps, though he didn't quite come to a halt. "I don't need coddling, Don. I might not like it when my team puts me under the microscope, but being short with them will only put an unnecessary strain on our working relationship."

"You weren't short with them," Don pointed out. "I was the one who cut things off. Not only am I a Fed, I'm going to be gone in three days. No harm done to your working relationship with them, and you're a little more comfortable." Don shrugged. "I don't see a downside."

 _There isn't one,_  Mac supposed,  _but that doesn't mean..._  Mac's train of thought trailed off as the pieces of the puzzle fell into place.  _The NYPD CSU is at your service,_  Mac had told him, and they'd both understood what he'd meant, even if he couldn't speak frankly in the middle of a crowded airport.  _You're a little more comfortable._

Don was taking care of his own.

Mac found his shoulders tightening with a shade of discomfort.  _This is how it works,_  he reminded himself.  _Unless you want to find a quiet corner somewhere and try to beat the hell out of him._  Mac forced himself to take a long, deep breath and relax his shoulders. When he looked over to see why Don had been so quiet, he found the other stallion watching him. Mac just shrugged. "Takes a little getting used to."

"Especially at work," Don commented.

Grimacing a little, Mac nodded. He'd always taken pains not to bring his private life into the workplace. Personal, emotional reactions invariably interfered with professional judgment and behavior. It didn't matter that they were sometimes unavoidable, it was still worth minimizing the effect.

They arrived at the break room, which was, thankfully, empty. They crowded around the coffee and attendant accessories for a moment, trading carafe and sugar and cream and stir sticks back and forth until they'd both doctored their cups as desired. Then Mac muted the TV and the two of them sat down at one of the tables and sipped their caffeine for a moment.

"Robert Davies," Don finally said, his tone thoughtful.

"Which begs the questions: why kill Carlos Esteban?" Mac asked.

"I don't think Esteban was meant to die," Don said thoughtfully. "We always assumed that the killer  _knew_  that Esteban was immunocompromised and that a less virulent strain of anthrax was used either because it was easier to come by or because the killer wanted to minimize collateral damage."

"But Robert Davies wasn't immunocompromised, and he presumably got the same anthrax," Mac mused, "which wouldn't have killed him."

"You wouldn't bother sending a warning letter to someone you expected to keel over," Don added.

"Right," Mac nodded. "And if the killer didn't want the primary target dead, then it's reasonable to assume that they didn't want Esteban dead either."

"Except that the primary target  _did_  end up dead," Don observed, brow wrinkling in thought.

"Not until  _after_  Esteban died, apparently accidentally," Mac pointed out.

Don narrowed his eyes. "In for a penny, in for a pound?"

Mac shrugged. "Might was well be hung for a sheep as a lamb."

"Might as well go the whole hog," Don returned, eyes twinkling.

"I  _could_  keep going," Mac said dryly.

Don laughed and waved him off. "I'll take your word for it. So," he paused to sip from his coffee. "This explains the escalation from anthrax letter to baseball bats, at least."

"It still seems like a sharp escalation to me."

"Not if you consider the timeline," Don argued. "They send the letters to Esteban and Davies and wait for Davies to take the warning to heart and back off of whatever he was poking his nose into. More than a week goes by and nothing happens. Maybe Davies is getting closer to whatever they didn't want him investigating, or maybe the idea that he apparently wasn't at all affected by a pretty serious warning just makes them twitchy. In either case, the tension is getting pretty high. Then they find out about Esteban's death--" Don broke off and frowned.

"Problem?" Mac prompted.

"Esteban's death wasn't exactly big news," Don said. "He was a federal agent, but for INS, which isn't exactly the sexiest agency, as far as the press is concerned. The papers weren't pushing too hard. I can't imagine anyone picked it up in  _New York_."

"Maybe they tried to track him down after Davies didn't back off," Mac suggested. "To make sure that the anthrax actually had an affect on someone. Maybe that's why they sent it to Esteban in the first place."

"Maybe," Don said, troubled. "Anyway, that's all speculation. Just assume for the moment that they find out Esteban's dead. Tensions are already high, suddenly they have a corpse on their hands, and the situation they were trying to put a lid on is only getting worse. Simple solution: kill Davies and it all goes away. Stefanos is collateral damage."

"But baseball bats?" Mac asked. "That's a little up close and personal."

"It does seem like a sharp escalation, but when emotions are running high..." Don shrugged.

"Hmmmm." Mac nursed his coffee for a minute thinking. "All paths of thought seem to lead to one place, at the moment," he said eventually.

"What was Robert Davies investigating?"

Mac nodded. "Exactly."

"We won't need to re-interview  _everyone_  from the original case, if we're going to focus on Davies," Don said. "But we're going to have to do some new interviews, people that the prior investigation might have overlooked because they didn't know that Davies was a target, not one of two victims of opportunity."

"I'll call--" Mac broke off in the midst of offering Flack's help. Completely aside from the fact that he wasn't sure it was his place to make the offer anymore, throwing another stallion into the mix was hardly a good idea.

"You'll call...?" Don prompted when Mac didn't go on.

"I was going to offer Flack's help," Mac said, grimacing.

Understanding dawned in Don's expression. "Ah," he said. "Probably not the best idea."

Mac tossed Don a wry look and finished his coffee. "It's well past quitting time, anyway," he said, "and you've had a long day. Can sorting out interviews wait until the morning?"

Don's expression took on a faintly amused cast. Mac had to suppressed a frown. What had he said to prompt that? But Don didn't give him any clues, just finished off his own coffee and nodding. "Yeah, it can wait."

***

Don could have called a cab, or co-opted a vehicle from the PD's motor pool, but instead he walked down to the parking lot with Mac and let the other centaur drive him to his hotel.

Mac wasn't like any other stallion Don had met. Not that he'd met that many, but he'd run into a couple, over the years. Every one of them had had a clear sense of their place, whether that place was dominant over a herd or not. Mac, on the other hand, seemed almost at odds with his own instincts, regardless of what those instincts were.

When instinct told Mac to fight, he yielded. But he couldn't just relax, accept that he'd yielded, and let Don lead. So he kept bouncing between challenge and deference, often between one sentence and the next. No wonder he'd done so well in the Marines; Don had never met anyone so in need of a clear, definite chain of command.

The drive to the hotel was made in comfortable silence. Don leaned against his door and watched Mac as he drove, making no attempt to conceal his attention. Mac glanced at him curiously a couple of times, but said nothing.

 _Don't get in too deep here,_  Don warned himself.  _It doesn't matter that he's given himself over to you. His life is 3000 miles away from yours. You can't give him what he needs in three days._

 _Not even if you want to._

 _Not even if every instinct you have is telling you that you_ have _to._

 _Not even if you know that he's the one person in your life who has it in him to accept being taken care of the way you want to do it._

Don took a deep, quiet breath, drawing in the scent of the other stallion. They pulled into the driveway of the hotel and Mac started to slow to drop Don off. Don found himself speaking. "Come in and have a drink with me."

Mac glanced at him, then smoothly pulled through the driveway and found a parking spot. They carried Don's suitcase and briefcase and the box of files Mac had put together up to Don's hotel room and dropped them there before heading back down to the bar in the lobby.

Ten minutes later they were seated at a table in the corner with a pair of beers. "I'd ask you what you think of New York so far," Mac said, smiling a little, "but all you've seen is the airport, the lab, and this bar."

"Given what we spent the last eight months doing, those are all the important parts," Don said, smiling back. "Seriously, it's good to be here. To work with you in person."

"Likewise," Mac replied. "Except for the being here, of course. I'm always here." Don swallowed a laugh, but he couldn't help grinning. After a moment Mac ducked his head a little, turning his beer in circles. "Conversation was easier over the phone."

"No," Don countered, "we just always started out with something to talk about--the case. But today we've already spent most of the whole day talking about that."

"Does that mean we have nothing left to talk about?" Mac asked, quirking a lip.

"What, like we always talked about the case on the phone?" Don sipped from his beer. "We just have to learn how to get going from a different starting point, that's all."

"Got a starting point in mind?"

Don tilted his head, studying Mac for a long time. Oddly, Mac seemed  _less_  relaxed now than he did when he'd been at work.  _Is he always so restrained in social situations,_  Don wondered,  _or is it because we've never met in person before? Or because I'm a centaur?_  He wanted to ask, but he didn't want to make Mac feel even more awkward. He wanted him to relax, to laugh again. After eight months of hearing that warm, rough sound, getting to see the smile and the light in Mac's eyes that went with it was a treat.

So he went with a neutral topic, but one still personal to the two of them. "Where do you go to change, living in Manhattan?"

Mac sipped his beer. "I rent a storage unit a few blocks from my apartment."

Don froze with his drink half way to his mouth. "A  _storage unit?_ " he repeated.

"Yeah." Mac frowned. "What's wrong?"

"How big is it?" Don demanded.

Mac set down his beer, looking confused. "20 feet by 20 feet. Why?"

"You can't possibly get up to a canter in there," Don said definitely. "God, Mac. When was the last time you went  _running?_  Really stretched out?"

"I go running all the time--"

"I didn't mean in  _this_  shape," Don said firmly. "And you know it. Spit it out."

Mac blinked. "I...don't really remember. Not since I started with the crime scene unit, at least."

Don swore. "You officially  _do_  work too much, if you don't at least get out of town every now and then to go running. I don't know how you stand it."

"I'm just used to it, I suppose," Mac said. "I like the city. I don't find it claustrophobic or artificial or anything like that."

"Liking the city doesn't have a thing to do with it," Don argued. "I like L.A. a lot, it's my city, but it still feels fantastic to be able to run as hard as I want, to feel my muscles-- _all of them_ \--warm up and get loose and relaxed."

"You go out often?" Mac asked.

"A couple times a month," Don confirmed. "More often when I'm in a bad mood."

"I suppose it's easier to find somewhere close in L.A. than it is in Manhattan," Mac commented wryly.

"Fair enough," Don admitted. "But I still think you could use a vacation day or two every now and then and go away somewhere to stretch your legs properly. Don't you get itchy for it?"

Mac shrugged and dropped his eyes to his beer bottle. "I don't spend that much time in my other shape, Don. I never have, not since I left the herd."

Don tilted his head curiously. "Why not?"

"At first it wasn't convenient and I wasn't sure how to make arrangements without stepping on the toes of the herd's new stallion. Then I joined the Marines and it wasn't  _possible._ " Mac's eyes went a little distant. "I met Claire while I was in and once I was discharged I had to be very discreet about changing."

Don's eyebrows rose. "She didn't know?"

"Not at first." Mac looked at Don and there was an odd combination of sadness and amusement in his eyes. "I wasn't quite discreet enough about sneaking off to change. She was convinced I was cheating. When she confronted me, I told her the truth."

Don let out a breath. "I know you stayed together, so I guess she was okay with it."

"Yeah," Mac said quietly. "Claire was...amazing."

"If you haven't changed anywhere but a storage room since you came to Manhattan," Don said quietly, "I guess you never took her riding with you."

Mac shook his head. "No. To be honest, I've tried as hard as I could to be as human as I could be."

"Why?" Don asked, startled. "It's not a matter of degree, Mac. Neither of us are human. We never will be."

"I know." Mac paused, eyebrows drawn down, and was silent for a moment. Don waited, giving him room to think. "I never felt any particular drive to lead a herd," Mac said finally. "I wasn't fostered out until I was fourteen. It was...disorienting to be more or less on my own after having such a stable, prescribed position in life. I drifted until I joined the Corps, looking for somewhere to belong. From then on I was immersed in human power structures and..." Mac shrugged. "Well, when in Rome, do as Romans do."

"Didn't that confuse your reactions sometimes?" Don asked.

Mac shot him a wry look. "I've told you about some of the personnel problems I've had. What do you think?"

Don involuntarily returned the expression. "You wish sometimes you'd started out with a different management style?"

"Occasionally," Mac admitted, "but I can't honestly see what would have worked better. Except maybe a little more consistency, but I wasn't going to get that no matter which direction I went. Either my instincts would creep in and unsettle things or my experience with human nature would make me second guess my instincts."

"It  _is_  possible to balance the two properly," Don said, taking a long sip from his beer.

"Patently," Mac said, nodding in acknowledgment at Don. "How did you settle things in your mind?"

"Easy," Don shrugged. "Megan, Colby, and David aren't my employees. They're my herd."

"Don, a herd stallion  _owns_  his people," Mac argued, frowning.

"Sure," Don said easily. "And I own Megan, Colby, and David. And Charlie and my Dad." Don paused and looked momentarily bemused. "And Larry, which sure as hell took me by surprise."

Mac rubbed at his forehead briefly. "But they're human. Humans don't own each other."

"I'm not human," Don replied. "It's not about how  _they_  see the relationship. It's about how  _I_ see it. Privilege of being herd stallion."

"And they're okay with this?" Mac asked skeptically.

"Oh, they don't know," Don said, smiling a little.

Mac paused before taking another sip of his drink and stared. "I know you said your family tends to forget that you're not human," he said, "but your team? Your relationship with them has to have a lot more elements of dominance to it. How could they  _not_  know?"

"It helps that they don't know I'm a centaur," Don said wryly. "And, to be perfectly honest, growing up with a human family probably contributed a lot to how much flack I'm willing to take from my people and how much obedience I require from them. I don't need to jump down their throats to reassure myself that I'm in charge. As long as I listen to them and trust their judgment, they always come back to me for direction."

"And the protective instincts don't get you in trouble?" Mac asked.

Don smiled. "Depends on how you define 'trouble.' Megan has called me on the protectiveness a couple of times and I know they all hate it when I pull them off active duty, but they let me do it. It's actually harder with Charlie. Not only is he totally oblivious to half the dangers around him, he doesn't acknowledge my authority to judge the risk inherent in a situation and determine his place in it." Don frowned, remembering. "He walked right into the line of fire of a sniper once."

Mac's eyebrows rose. "And you still let him work with you?"

"Believe me, sometimes I wish I'd never dragged him into my professional life." Don finished his beer and, seeing the low level of Mac's own bottle, signaled the waitress for another round and strung his words together mentally while he waited. When the new drinks had arrived, he went on. "Even if Charlie's analyses didn't help us save lives, I don't think I could cut him out of that large a part of my life. I tried once, when it looked like a couple of suspects in a case were threatening him."

"What happened?" Mac asked intently.

"Charlie got himself assigned to the case under someone else's authority," Don said, prompting a wince from Mac, "and I learned something, aside from the fact that Charlie is too proud and stubborn for his own good. The members of a herd are never dead weight. Everyone really does have their place, and messing with that throws everything off."

"But don't those places change? Charlie didn't always work with you. You'd even been back from Albuquerque for a couple of years before he started consulting on your cases regularly," Mac pointed out.

"Sure they do," Don said. "And if I really wanted to, I  _could_  force Charlie to the periphery again. But doing that would change every other relationship in the herd, too. I have to weigh the risk to Charlie against the smooth and positive functioning of the members of my herd with each other and with me."

"And Charlie's safety doesn't win?" Mac asked.

The question could have been accusatory, but not only did Mac's tone of voice--something Don had a lot of experience interpreting--not hold even a shade of that, a quick breath confirmed it wasn't showing up in his scent either. Don suppressed a smile of pleasure at having that extra dimension of communication come through so clearly. "No, it doesn't," he said aloud. "Believe me, I insist that the whole team do everything they can to minimize the risk to him, but I know that cutting him out completely would not only permanently damage my relationship with him, it would also make working with Megan awkward, given her relationship with Charlie's best friend, and it would disappoint my Dad, who loves that Charlie and I have grown close again. And that's not even considering the friendships Charlie has been developing with Colby and David, or their perception of me as a leader, if I'm willing to put a controllable risk to my brother above the lives of people I'm charged with protecting."

Mac shook his head. "I think I'm relieved that I decided to aim for human responses," he said wryly. "Even if they do come into conflict with my own instincts sometimes."

Don chuckled. "Okay, yeah, it is complicated, but it's also rewarding."

"And you don't ever wish you'd handled it differently?"

Don shook his head. "No. Though sometimes I do wish my people were a little more willing to let themselves be taken care of."

"Humans have a different concept of what that means than we do," Mac pointed out.

"I know, and I knew what I was getting myself into when I adopted them," Don said. He hesitated, then said quietly, "But it  _would_  be nice to have someone who understands it the same way I do."

Mac looked down at his beer, turning it in circles with his fingers for a moment. "Even if that person is only going to be within reach for three days?"

"Within physical reach for three days," Don said. He smiled a little. "I think we did pretty well over the phone. And hey, one day you might find yourself in L.A. and I can take you out for a _real_  run."

They fell silent for a moment and an awareness of just how tired he was edged into Don's consciousness. The relaxing effect of the alcohol probably wasn't helping with the heaviness of his eyelids. For a moment he struggled for alertness, but his body was insistent. "I think I need to go to bed," Don said reluctantly.

"It's late," Mac affirmed. Neither of them moved. "Would you like me to pick you up in the morning?" Mac asked eventually.

 _It would make more sense to rent a car._  Don thought, but found himself nodding instead. "Yeah. Is seven too early? I want to make best use of our time."

"Seven it is," Mac said.

For a moment they both continued to sit there. Eventually Don knocked back the last of his beer and signaled the server so that he could charge their bill to his room. When she was gone the two of them stood and left the bar together. Don found himself walking Mac out to his car. Mac gave him a quick glance, but made no objection.

They stood by the car for a moment. "Drive safe," Don said finally, feeling foolish.

Mac caught and held his eyes. "I will," he promised quietly.

Don smiled in acknowledgment and forced himself to turn and walk back into the hotel.

When he'd returned to his room Don showered quickly before pulling on a t-shirt and a pair of boxers and crawling into bed. He stretched out and stared up at the ceiling for a long time, unable to slip into sleep immediately despite how tired he was.

 _Mac is a centaur._  Don turned that awareness over and over in his mind. It reminded him of Gibbs and Tony and how  _good_  it had felt to be understood, to have all the right scents in his nose. But for all the similarities, Mac wasn't much like Gibbs at all. Gibbs was a hard, intense man. There was warmth in him, but his hardness wasn't just a mask for that warmth, it was real.

Mac, on the other hand, worked at being authoritarian. No wonder he overdid it sometimes; it was safer to err on the side of coming down  _too_  hard than it was to go too easy and find your authority slipping away. It made Don wonder what Mac would be like when he let himself relax completely. There was a sense of...comfort that leaked out sometimes. It was something in the quietness of his body language, the set of his jaw, the dark eyes...

Don slept.

***

Don was waiting in the lobby when Mac pulled up in front of the hotel. He climbed into the passenger seat, the box of files on his lap. "We should have just left these in your office," he said ruefully. "I just crawled into bed and went to sleep. Didn't even glance at them."

"Apparently we only work too hard when we're working alone," Mac said, smiling a little.

Don laughed. "Yeah, maybe. It's easier to be a workaholic when there's no one around to call you on it."

The drive in to the lab went quickly and the two of them ensconced themselves in Mac's office and started spreading files out and sorting them into stacks. Less than an hour later they'd made use of every flat surface within reach of the desk, including the tops of the stacks of evidence boxes, and Don was transcribing a list of names and addresses as Mac figured out a sensible order to visit the dozens of people they were going to have to re-interview.

Don didn't bother to look up at the tap on Mac's door; no one was likely to be looking for him, after all. But even as he registered the draft of air when the door opened, the scent struck him: another stallion. Spine stiffening, he'd already started to shift his gaze when Mac spoke.

"Don."

Don frowned at the wariness in Mac's tone of voice, but Mac wasn't looking at him. He was looking over Don's shoulder.

Which was when Don remembered that Flack's first name was  _also_  Don.

Mac stood and started to circle his desk. Don reacted on pure instinct. Mac was  _his_  and there was a hostile stallion in the room. He was up and out of his chair instantly, facing the threat, one hand reaching behind him to both confirm Mac's location and tell him not to take another step forward.

Flack was tall and lean. Don ran an experienced eye over him and knew in seconds that Flack would be faster, but that he himself was almost certainly stronger by a decent margin.  _Best to get him in a clinch, not give him room to maneuver. He won't run, but give him enough space and he'll dance right around you._  Remembering his conversation with Mac the night before, Don factored in the likelihood that he spent far more time in centaur shape than Flack did.  _Not to mention that you've had recent experience fighting in that shape,_  Don reminded himself.  _Don't take it for granted that he hasn't had any, but the chances are pretty good that you've got the edge on him there._

"Mac," Flack said warily, eyes never leaving Don, "who is this?"

Don waited tensely, but Mac was silent.  _Good._  "Don Eppes," Don said shortly. "FBI out of the L.A. office."

Flack raised an eyebrow. "You're a long way from your turf."

"My turf is right here," Don said evenly.

Flack's other eyebrow went up, too, and he deliberately leaned to the side and looked past Don at Mac. "Mac?"

Don bit down on the need to answer for Mac.  _You're in his office, this is his coworker, and he's already made his place perfectly clear by letting you step in front of him,_  Don reminded himself, taking a subtle breath.  _You know better than to push it this soon._

After a moment Don sensed Mac moving, but he didn't step past Don, he just moved to the side a little and forward far enough that his chest brushed Don's shoulderblade. "I've put the lab's resources at Special Agent Eppes's disposal," Mac said carefully.

Don suppressed the urge to nod at Mac's wording. He'd managed to include his own sphere of influence without implying that Flack should also be at Don's disposal.

"Was there something you wanted from me?" Mac went on neutrally.

Flack paused, looking from Don to Mac and back again, his brow wrinkling. "Is this a temporary agreement?" he asked instead of answering, and flicked a finger between Don and Mac.

"No," Don said flatly.

Flack's chin came up a little at the definitive word. Don drew in a deep breath, trying to gauge how aggressive Flack was feeling. The result made the muscles of his neck, shoulders, and back knot almost painfully. Don didn't know why Flack had chosen to back down in favor of Mac years ago, but it was teeth-grindingly clear that he wasn't going to do it again.

"And what happens when you go back to L.A.?" Flack demanded. "Did you even consider that before you stuck your nose in where it doesn't belong and screwed up a carefully balanced situation?"

"How this works after I leave New York is for Mac and I to work out," Don said. "It's not your business."

"Of course not," Flack said bitingly. "It's not as if I'm going to have to  _work with him every day_ after you leave."

Don's stomach twisted at the thought of a hostile stallion in such proximity to one of his own. He buried the reaction.  _Not the time or place, Don._

"Flack--" Mac began, but the other stallion cut him off.

"I'm not a rookie detective anymore, Mac," he snapped. "I'm not going to be putting my career in danger if I have a little dust up with a more senior officer. I've got a little weight behind me now, which means I don't have to play it safe."

With Mac still standing behind his shoulder Don couldn't see him, but the tone of his voice communicated Mac's startled realization vividly. "Is that why you came to me like you did?"

"What did you think was going on there?" Flack asked.

Mac eased forward to stand next to Don's shoulder. Don shot him a sidelong glance, but let him move. For the moment. As long as Flack was on the other side of the office. Don took in another quick breath. Mac was relatively calm, at least. Still, Don caught his eye and gave him a long, steady look. Mac nodded marginally and turned back to Flack. "I never knew," he said. "I was just glad we weren't going to have to fight it out."

"Yeah, well, we might have to after all," Flack said, glancing at Don.

Mac frowned. "Why? Hasn't it been working?"

"Sure it has," Flack agreed. "Better than I expected, really. You always treated me pretty much like a human. It made it easier to take. But dominance isn't transferable. You gave it up," Flack stabbed a finger at Mac. "You don't own me anymore and I'm not planning on baring my throat for Eppes over there, so tell me, what the hell do we do now?"

Silence fell, and was broken by the sharp click of high heels. Don risked taking his eyes off of Flack long enough to glance through the glass walls of Mac's office at the corridor. Stella stood there, a file in her hands, looking through the glass at the tableau the three of them made with a sharp expression. She spotted Don looking at her and snapped back into motion, quickly stepping into the office with them and shutting the door behind her. She didn't close the drapes, but Don supposed that would have attracted more attention than their little confrontation, anyway.

"Well," Stella said, leaning back against the glass door and tapping the edge of the file against her other palm. "The tension in here is thick enough to require a diamond chain-saw, never-mind a knife."

Mac glanced at Don quickly, a request for permission, and Don remembered that Stella was in the know. He nodded and Mac turned to Stella and let out a breath. "Don...Don Eppes, that is," he clarified, "is a centaur, like me and Flack."

Stella blinked. "What, are you all having a convention or something?"

Don couldn't help but snort at that. "No," he said. "Just a little disagreement over who is in charge of what and who."

"I thought you and Flack had that worked out," Stella said to Mac, frowning.

"We did," Flack answered. "Until Eppes entered the picture."

"But he's only going to be here for three days," Stella protested.

Mac grimaced. "It's...a little more complicated than that."

"You know what?" Stella raised her hands, the file still clutched in one. "Right now, I don't even want to know. As much as I appreciate what taking over for Mac for three days is going to do for my chances the next time I put in for a promotion, it does mean that I've got half again as much work to do." She turned and started to push the door open, looking over her shoulder at them as she did. "Just...avoid each other for three days, okay? Then instead of working out how things work between Mac and Flack, and Flack and Eppes, and Mac and Eppes, you only have to work out things between Mac and Flack." The door softly  _thunked_  closed behind her.

The three stallions traded wary looks. " _Did_  you want something from me?" Mac asked eventually, since the question never had been answered.

"I heard you were opening up a cold case and thought I'd see if you needed help with the interviews," Flack said, his eyes drifting inexorably back to Don.

"We've got it covered," Don said.

Flack paused, then nodded slowly. "I'll be working with Danny and Lindsay," he said. He looked at Mac, then visibly abandoned whatever he'd been about to say and left the room without ever entirely taking his attention off of Don.

Mac let out an audible breath. "Well, that was...interesting," he said wryly.

"Interesting is one word for it." Don rolled his head on his shoulders, trying to release some of the tension. "Listen, are these interviews well enough sorted? We need to get out of the building."

Mac scooped up the list Don had been working on and flipped through it. "We might end up doing a little retracing of our footsteps later in the day," he said eventually, "but for the most part, we're organized."

"Good." Don plucked his jacket off the back of the chair where he'd draped it. "Let's head out."

***

Mac glanced across the stoop of the house whose door they were about to knock on and smiled internally. In that suit, shoulders pulled back professionally, eyes masked by sunglasses, Don was the very picture of a Fed. He rapped on the door and immediately reached into his pocket for his ID. When the door opened he had it ready, flipping it open to display both badge and ID. "Lynn Rogers?" Don asked. "Special Agent Don Eppes, FBI," he said calmly. He flipped the ID closed and used it to gesture at Mac as he put it away. "Mac Taylor, NYPD." ID properly stowed, he removed his sunglasses and let his expression relax just a bit. "May we come in?"

Mac admired his technique. Make a professional first impression, then put them a little at ease. As much as they could be with the FBI on their doorstep, anyway.

The woman who had answered to Don's knock stepped back from the door and held it open for them. "Of course," she said. "What's this about?"

Don held his answer until they were seated in her living room. "Robert Davies," he said finally.

"Robert..." For a moment only confusion showed on Rogers's expression. Then it cleared. "Professor Davies? But he's been dead for years."

"Yes, ma'am," Don confirmed. "The case has been reopened. New evidence."

"In a home invasion?" Her brow wrinkled. "That gets the FBI interested?"

"We no longer believe it was a home invasion," Mac said quietly. "Professor Davies may have been targeted."

"Targeted?" Surprise showed on her face, but no dismay, for all that she'd worked with him for more than a decade. Presumably the years since he'd first been killed had muffled the emotion of the event. "By who?"

"That's what we're trying to find out," Don said.

"Do you remember if Professor Davies was having trouble with anyone at work?" Mac followed up. "A fellow faculty member? Staff? Students?"

Rogers shook her head. "It was nine or ten  _years_  ago." She smiled sheepishly. "I'm fortunate if I can remember what we talked about in last week's lecture."

"Anything at all would be helpful," Don said.

Rogers's eyes went distant and she raised a hand and tapped her cheek thoughtfully. "Robert Davies... As I recall, his research wasn't anything particularly special. He was a little more adventurous when he was younger," she smiled wryly, "and still aiming for tenure. But later on he was always saying he if couldn't avoid unwelcome interest in his personal life, he was damn well going to avoid it in his professional life."

"His personal life?" Don asked, tilting his head inquiringly.

"Evander's immigration hadn't come through when he and Robert first met," Rogers explained. "They were under a microscope for a long time while INS decided whether or not to approve Evander's application." Don nodded his understanding and gestured for her to go on. "Anyway, by the time he was killed Robert's research wasn't anything to write home about. He'd started spending more time on the teaching side of things, really. He was very involved with the undergraduate courses."

"Did that bother anyone?" Mac asked.

Rogers's eyebrows flew up towards her hairline. "Bother anyone? Hell, no. As far as most professors are concerned, classes and students are a necessary evil. They're about as far down the priority list as it's possible to get. Volunteering to take on more instructional responsibilities meant Robert was lightening the load for everyone else. I can't say it exactly made him a popular guy--most of the faculty didn't pay enough attention to realize where the relief was coming from--but it did make everyone happier."

"What about the head of the department?" Don asked. "Low profile research wasn't going to do their reputation any favors."

"True," Rogers allowed, "but every department has a few duds. At least Robert more than pulled his weight in  _one_  area. There were a couple of faculty floating around that some of the staff honestly thought had died until we had to update the phone directory."

"If Professor Davies spent most of his efforts on teaching, what about his students?" Mac asked.

Rogers shrugged. "I'm afraid I didn't pay much attention to the undergraduates outside of my own classes. I know that Robert mentored several students. They were always coming and going from his office, running errands for him or using his reference library or just going out for coffee sometimes."

"Did he mention any concerns regarding his students?" Mac spread his hands. "Maybe even just that he was having an extra meeting with one of them, or a concern that a personal issue was impacting their academic performance?"

"No," Rogers shook her head. "Nothing..." She trailed off, frowning now. "Actually," she said slowly, "there was something a little unusual. Robert tended to pick up new proteges at the beginning of term and those would be the students you'd see around his office for the rest of the year. But in the month or so before he was killed, he had meetings with half a dozen kids who weren't regulars of his."

"You didn't mention that at the time of the original investigation," Don commented.

"The detective asked about people with a grievance against Robert, whether or not he'd argued with anyone recently, that sort of thing." Rogers shrugged. "As involved as Robert was with the students, there was nothing sinister about his meeting with some of them. It was just a little odd, that's all."

Mac nodded contemplatively and let Don take over the questioning, listening with half an ear. Why would a university professor suddenly need to meet with multiple students in whom he'd had no earlier interest? He supposed there could have been a problem with a recent exam or assignment, but the timing seemed too coincidental.  _As coincidental as Esteban's INS cases leading us to the_ real _connection between the murders,_  Mac thought wryly.  _As coincidental as both Don and I turning out to be centaurs._

Still, he kept it in mind as they questioned four more of Davies' former colleagues and one of the students he had mentored.

After they'd left the student in her apartment they headed for their next stop eagerly--lunch. Mac folded himself into the diner's booth and picked up the menu only long enough to confirm that what he wanted was available. Don took a little longer with the menu, browsing the exotic burger choices this place specialized in.

 _If I didn't have a centaur's sense of smell,_  Mac thought,  _I'd never know he was a stallion with a herd--unconventional though it might be--of his own._  Don didn't have the...edge Mac associated with mature stallions.  _Not that I have much basis for comparison,_  he thought wryly. The herd stallion of his childhood and Flack were the only ones Mac had ever known. Still, both of them had always put a little extra pressure on his nerves.  _A little like Don did at the airport,_  Mac realized, blinking to himself. But that tension had been ebbing away ever since, leaving behind only an unfamiliar, baseless anxiety that Mac couldn't seem to resolve.

Mac hadn't really expected it to work the same way between himself and Don as it had between himself and Flack, but the  _degree_  of difference was startling. With Flack the tension had become manageable, but that was all. With Don...Mac swore he was more relaxed than he had been  _before_  he'd known Don was a centaur.

Unexpectedly, Don looked up and caught Mac watching him. "Am I taking too long?" he asked, a little sheepishly. "It's been awhile since I went to a restaurant where I didn't know the menu by heart."

Mac waved off the implied apology. "I'm not surprise, given your memory," he said, feeling the edge of his mouth curve up.

Don's expressive face transformed into a mirroring smile. "Given yours, why did you even look at the menu?"

"Force of habit," Mac said, shrugging. "I try not to advertise just how good my memory is."

"People tend to notice perfect recall," Don commented, and Mac nodded.

"I could wish accurate memory was a more common trait," Mac said. "Forget not having to be discreet, think of the time saved in interviewing witnesses. A hundred little questions to tease out that one relevant detail, even when you know what you're looking for."

"Right now I'd settle for knowing what to look for," Don said wryly. He closed his menu and set it down on top of Mac's as a signal for their waitress that they were ready to order.

Mac waited until she'd come and gone before responding. "Did you notice that several of Davies' colleagues noticed he'd been meeting with unfamiliar students in the month before his death?"

"Yeah," Don said, "but he's a college professor, Mac. God knows random students are always wandering into Charlie's office or stopping him after class to make an appointment for a hundred different things."

"Charlie is a young, approachable, rock star of a professor," Mac said dryly. "Davies isn't exactly in the same category."

"So you think that's the key? These student meetings?"

"They're the only thing that's even marginally out of place so far."

Don hummed thoughtfully. "We can at least try to track one or two of the group down. We've got what, eight students to interview this afternoon? Maybe one of them will remember something."

Mac frowned. "If there was a problem with the unfamiliar students, the chances aren't very good that Davies's proteges knew them. Involved, committed students and problem students don't typically mix much."

"But involved, committed students spend more time in their professor's offices," Don pointed. "Even if Davies always asked them to leave when one of the problem students came in, they'd still see who was staying while they left."

Their waitress appeared at their table and the two stallions paused to give her their orders. When she was gone Mac leaned back in his seat and took a sip from his water while he thought. "Assuming any of Davies's students remember seeing unusual students in his office," he said, "how are we going to find those particular students? Even if they have appointments in Davies's date book, we're not likely to get an exact date out of anyone this long after the fact."

Don shrugged. "The university will have a record of all his students during that semester. If we have to, we get general descriptions and interview anyone who even remotely matches."

Mac grimaced at the thought. "This is the problem with cold cases: so much evidence is lost."

"It doesn't help," Don said, a smile curving his lips, "but more often than not it's legwork that moves cases forward, not piles of evidence."

"But interviews aren't reliable when you're building a case," Mac argued. "You can only trust the evidence."

"I didn't say we  _trusted_  interviews. Heck, I didn't mention interviews at all," Don returned. "I'm just saying, most cases don't break because some piece of key evidence suddenly turns up. They break because someone spent all day knocking on doors in apartment buildings, or calling up every G Daniels in the phone book, or watching thirty-six hours of videotape."

"All of my cases have been heavy on the evidence," Mac said, frowning.

Don laughed. "Of course they have! You work with the evidence. If a case doesn't have much, you don't see much of it."

"Everyone always seems pretty happy when it turns up," Mac commented. He suppressed the urge to fidget, suddenly aware of that anxious, restless feeling again.

"Well, sure," Don said easily. "I didn't say we didn't  _want_  it. Hard evidence can make things a hell of a lot easier. But it isn't the be all and end all, either."

"That seems like kind of an odd attitude to take," Mac said, "given how often you work with your brother these days."

Don snorted. "Don't tell Charlie this," he said dryly, "but I don't really consider his help to amount to hard evidence."

Mac furrowed his brow. "But you trust it."

"Sure," Don agreed, "because it works. But a stack of paper an inch thick that requires a Ph.D. to interpret isn't something you can show to a jury and expect them to understand."

"It only counts as evidence if I jury can understand it?"

"You know that's not what I meant," Don said. "There's a difference between the evidence and information we use to break a case and the evidence and information used to support a conviction. I try to give the courts something to hang their cases on aside from Charlie's analyses. Anything that complex is too easy to attack."

Mac hummed in reluctant agreement. One of the most important things they learned when he and his team were needed to testify was to keep their explanations simple and direct, even if it meant glossing over technical information that, theoretically, made their conclusions more solid.

Don fell silent then and a thoughtful crease appeared in his forehead. Their waitress returned in the meantime with their orders, but Don didn't start eating right away. "I should get Charlie involved again," he said, reluctantly. "Now that we know Davies was the primary target, not Esteban, the math will probably start making sense. Not to mention the files on all his students will provide a pretty good data set for him to start with."

Mac knew that Don was right, but the thought of bringing Don's brother into their case still irritated him somehow. "It took Charlie months to get around to looking at the data the first time," he said aloud. "You aren't going to be in town that long."

"It only took him months because it was low priority," Don pointed out, frowning.

"Has that changed?" Mac asked. "A new lead doesn't make this a hot case. It's important to you and me to find whoever killed these men, but they haven't killed anyone else. There's no immediate danger. This case is about justice and closure, not saving lives. Without that urgency, what reason does Charlie have to prioritize?"

"He'd do it if I asked him," Don said, but his expression had grown thoughtful. He picked up a French fry and bit off half of it.

"I don't doubt he would," Mac said. Don had a herd stallion's command presence, though he didn't project it the way many did. It was more of a sense that he was grounded, which invited trust and encouraged cooperation. It was a presence Mac had never found easy to tap into himself. "But do you really want to push for it on this case, when we don't really  _need_  it?"

Don shot Mac an intent look. Then he smiled a little. "You really don't want Charlie working on this one, do you?"

"Do you?" Mac asked, eating one of his own fries.

Don waved a fry at him. "Not what I asked, Mac. Have you got a problem with working with Charlie?"

"I wouldn't be working  _with_  him," Mac argued. "It's not like he's going to fly out to New York for this."

"Mac," Don said, voice going a little hard. "Charlie is my brother. Now quit avoiding the question."

Mac set his jaw stubbornly for a moment, but Don held his gaze, and eventually Mac consciously forced himself to relax the muscles. "We've spent eight months slogging through this case together," Mac said finally. He dropped his gaze to his plate. "Maybe Charlie could swoop in and all but solve it at this point, but...I want to finish this the way it started. With you and me. There's no reason we can't do that. It's not going to cost anyone anything to break this one the old fashioned way."

Not to mention if they broke the case in less than three days, the Bureau might insist Don return to L.A. early.

There was a long silence. Mac looked up to find Don watching him intently. Then the other stallion broke into a broad grin. "All right," he said, popping a fry into his mouth. "Charlie can sit this one out. Can't let him think I couldn't get along without him, right?"

Mac felt the tension flow out of his shoulders. "Right," he said, smiling back at Don.

***

"This is kind of depressing," Mac said as he shut the driver's side door of the car behind himself.

Don looked up at the apartment building they'd parked in front of. Michael Sanders lived on the eighteenth floor. He'd long ago learned how to clamp down on the instinctive fear and walk around hundreds of feet off the ground--which was a damn good thing, given that his office was in a high rise--but he had to admit that one of the nice things about L.A. was that it was a city that tended to sprawl, rather than soar. "What is?" he asked in response to Mac's question.

They walked up to the building's door and Mac pulled it open, allowing Don to step through first. "These people were Robert Davies' proteges," he said. "Presumably, he took a significant interest in them. Helped them get through their degrees, got them started in their degrees. But almost none of them can remember him well enough to tell us anything useful."

"They  _do_  remember him, Mac," Don commented. "They just can't remember such a specific time period. That's not unusual, especially ten years later. Just think, how many people have you spoken to who can't even remember where they were at breakfast two days ago?"

The two of them walked into the elevator and Don hit the button for the eighteenth floor. "And when they do remember, they don't usually remember accurately," Mac commented in agreement. "I just...you'd think that the people who actually had a significant impact on their lives would be carved a little more deeply into their memories."

Don shot Mac a sidelong glance. "They?" he commented. "Don't start thinking of yourself as apart from humanity, Mac. Thinking like that will mess up your head."

"I didn't mean it like that," Mac objected. "I just...sometimes feel like I'm forgetting who I am. I need to give myself a little shake."

The elevator arrived on the eighteenth floor with a chime and the doors slid open. Don stepped out and paused to let Mac come up beside him. "I don't think that backing and forthing is doing you much good," Don commented. "You try to handle your people the way a human would, doing your best to be human yourself. Then you realize you haven't been behaving like a centaur and you swing back in the other direction." Don stopped, reaching out a hand to halt Mac beside him. "You need to relax. Learn to trust your instincts."

Mac just looked at Don for a long moment. Eventually he shook his head once, but it didn't seem to be in disagreement. "It's not that easy. I've always tried to reason my way through things," he said. "Look at the facts. The evidence. I knew I could trust that."

"Don't you ever trust  _people_?" Don asked. He tried to imagine what life would be like without his dad's advice or his team to back him up or even Charlie's wild math to shake loose stuck cases and had to suppress a shiver at the thought of all that  _emptiness._

Mac was quiet. "I trusted Claire," he said softly.

 _Ah._  "And Stella, right?" Don added gently. Stella knew he was a centaur, anyway. He  _hoped_ Mac trusted Stella.

"Of course," Mac said, smiling a little.

Don touched Mac's arm briefly and nodded down the hallway. "We better get going on this interview."

"Before someone reports suspicious characters loitering in the hallway," Mac said dryly.

Don grinned at him and turned to take the last few steps down the hallway. They arrived at Michael Sanders' doorway and Don knocked briskly. After a moment with no answer, he knocked again.

The answer from within was faint. "Just a second!"

Don traded a glance with Mac and they waited. After a moment there was the sound of a couple of locks disengaging and the door swung open. Michael Sanders was tall and blond, his hair short and combed neatly into place, right down to the last hair. Don could smell the fresh gel. Sanders smiled at them sheepishly, still knotting a tie under his chin as he stepped back from the door.

"Sorry, officers," he said. "I'm supposed to be in court in an hour. Come on in. What can I do for you?"

"How did you know we were cops?" Don asked curiously, stepping into the apartment.

"I work with a lot of police," Sanders explained, which made sense. According to his file, he was a New York county prosecutor and his record suggested he was aiming for Assistant District Attorney, eventually. He finished knotting his tie and glanced around, patting a jacket slung over the back of a chair as if to reassure himself of its presence. Given that he next touched the handle of his briefcase--sitting on the chair the jacket was slung over--and his keys, which were resting on the kitchen table in front of the chair, he probably  _was_  reassuring himself. "You have the look. I can't stay long, I really do have to be in court, but a couple of minutes shouldn't make me late. What can I do for you?"

"We're working on a cold case," Don explained. "The Davies/Stefanos murder. I don't know if you'd remember it, you were--"

"Twenty, and in the junior year of my undergraduate degree," Sanders said, his expression darkening for a moment. "I was waffling between law school and going for my PhD at the time. What happened to Robert...it tipped the scales."

Don exchanged a glance with Mac and read the same hope in his eyes that he felt. Maybe this guy would remember more. "According to the file, you were interviewed by the detectives on the case at the time," Mac prompted.

Sanders nodded, slipping his hands into his pockets. "To see if I remembered anything useful, they said," he recalled. Then he smiled, wryly. "Looking back, I know it was also to establish my alibi, but at the time I didn't think of it. I was in shock a little, I think."

According to the case-file, Michael Sanders had been researching a paper in one of the university libraries at the time of the murder. Both the librarian and the assistant who'd been helping him track down sources at the time had confirmed it. "Did you? Remember anything useful, that is," Don asked. There was nothing in the file, but it didn't hurt to ask.

Sanders shook his head, regret etched into his face. "No. I wanted to. I wanted so badly to know something that would lead them to the guys who killed Robert, but nothing I told them was useful."

"Not useful?" Mac asked. "Does that mean there  _was_  something you told them?"

"I told them pretty much everything leading up to that day," Sanders said. "Like I said, I really wanted to be able to help."

"Can you tell us what you told the detectives then?" Don asked.

"Why? I thought it was a random act. A home invasion." Don and Mac traded a quick glance. Sanders picked up on it, frowning suddenly. "Wasn't it?"

"We have some new information," Don said carefully, "that leads us to believe that Robert Davies was specifically targeted."

Sanders stared. "Jesus," he said softly. "Jesus Christ. Targeted. Um. Give me a second to remember, here." He checked his watch, hesitated, and turned to fish a cell phone out of the pocket of the jacket draped over the chair. He punched in a number, waited, and said, "Jackie? I'm going to be a few minutes late. No, no problem with the case. I've just been held up a bit. I'll tell you about it when I get there. Thanks." Hanging up, he let out a slow breath and seemed to relax a bit even as his brow creased in concentration.

"It was just after midterms," he said eventually. "Robert was getting a lot of visits from students who wanted to talk about their mark." Don grimaced at Mac, wondering if that shot their theory out of the water, but Sanders kept talking. "That's normal--some profs will let you talk yourself into a higher grade--but Robert was unusually tense and harsh about it this time. Usually he was really patient with students. He wouldn't let them bully him, but he was happy to explain where they had gone wrong, to help them fix the problem for the final."

"This time was different," Don said quietly, wary of disrupting the course of Sanders' memory.

He nodded. "Yeah. I never stayed in his office when he was meeting with other students, of course, but some of them talked to me about it afterward because they knew I had Robert's ear and they wanted me to help them out. He chewed out at least two of them, said stuff about earning their grades. That was weird. Robert never accused his students of slacking off. Not even when he thought they were; he thought that was unproductive."

"Did he do anything unusual after these meetings?" Mac asked.

"He marked all the exams over again," Sanders said immediately. "He'd never done that before. And then correlated the grades. He never did that before, either."

Mac frowned. "Correlated the grades?"

Don thought he knew what Sanders meant. "Is that when the prof sorts the papers in stacks of roughly equivalent quality and marks them relative to each other, instead of against some separate standard?" he asked.

"Yeah," Sanders confirmed. "Robert didn't like marking that way. He felt his students should be shooting for a particular standard, not just competing with each other." He hesitated. "I wouldn't have said this then," he said slowly, "but looking back...it was like he was looking for something."

"Do you remember which class he was marking?" Don asked.

Sanders frowned in concentration, but shook his head regretfully. "I'm sorry. I don't. But it was the winter 1996 semester and he couldn't have been teaching more than four courses then."

Four history courses would probably add up to hundreds of students. "Did Professor Davies seem upset with any students in particular?"

"No," Sanders said, shaking his head. "He was just really upset in general."

"Do you remember the day before his death, specifically?" Mac asked intently.

Sanders' frown deepened. "What day of the week would that have been?"

"A Wednesday."

Sanders raised his hand and rubbed it across his jaw as the thought, brow deeply lined. "Wednesday. He taught on Wednesdays, that semester. I remember because Wednesdays were the only days I had free, so it was a real pain in the ass that he couldn't schedule meetings on Wednesday afternoons. We ended up meeting on Tuesdays or Thursdays instead, usually when I'd normally have been taking a break for lunch..." Sanders trailed off for a moment. "The day before would have been Tuesday. We didn't meet...but he called me, left a message on my answering machine."

Don couldn't help but hope. "About what?"

"He had to cancel our Thursday meeting," Sanders said, more confidently now. "He needed to meet with someone else and that was the only time they had available."

"You're sure it was Thursday?" Mac asked.

Sanders nodded. "Yeah, I'm sure. And I think he was relieved. I could be remembering wrong, it's been a long time, but I think he was really glad he'd managed to arrange that meeting."

Don let out a quiet breath. "I don't suppose you know who the mystery appointment was with?" he asked, a little wryly.

Sanders smiled and shook his head. "Sorry. I wish I could help more."

"You've helped a lot," Don contradicted, holding out his hand for Sanders to shake. "I'm just greedy."

"Good luck," Sanders said, shaking first Don's hand and then Mac's. "I'm glad to know Robert hasn't been forgotten after all this time. I hope you catch the guy."

"We'll do our best," Don promised as they left the apartment. Sanders didn't need to know that it wasn't Robert Davies' murder that hadn't been forgotten. When it came right down to it, it wasn't Davies or even Stephanos that had kept the case on Don's desk for so long. It was just random chance that they were tied into Don's first unsolved murder. But it wasn't the mystery that mattered, either. It was doing what was right, finding the bad guys and putting them away.  _That_  mattered.

***

It would have been too easy for Robert Davies to actually have noted the Thursday appointment Michael Sanders had recalled in his daily planner. Oh, there was an appointment listed, but it was the cancelled meeting with Sanders, not the meeting that had resulted in the cancellation.

Robert Davies had been teaching four classes during the semester when he was killed. Don didn't even have to ask for numbers to know that there would be too many students for them to interview at all, never mind doing so in the course of a single day. They needed to narrow the field somehow. Unfortunately, the head of the department at the time had retired, and the current head had never known Robert Davies.

Fortunately, the former head wasn't too hard to find. Even more fortunately, he still remembered the last conversation he ever had with Robert Davies, in which the man had expressed a concern over a problem with his History 409 (American Foreign Policy, 1945 to Present) class. Don took a leap of faith, hoped that this wasn't just a coincidence, and called the current department head back to request a fax of the class list and any other pertinent information. They'd asked for the mid-term grades as well, hoping to find a pattern there, since that was approximately when Davies had started acting differently, but it turned out that wasn't the sort of thing the University hung onto. Maybe, they'd been told, if Davies was still teaching he'd have had them in the back of a filing cabinet somewhere. But when his office was cleaned out, all that had been trashed.

Which left Don and Mac with the class list, 27 complete college transcripts, and 27 perfunctory profiles. Don silently thanked God that History 409 had been one of Davies' smaller classes. They could have ended up with History 237 (Major Themes in American History), which had a class list of 162 students for the semester in question--and that was only the section Davies had taught.

By the time the two of them had tracked down the former head of the history department, jogged his memory, gotten back in touch with the university, and acquired all the files they needed it was well past five. They could have continued working in Mac's office, but they could study the files anywhere and Don had opted for the comfort of his hotel room and the wonder of room service.

He and Mac sat on the floor of Don's hotel room, surrounded by a sea of papers, two room service trays safely ensconced on the bed. Don set down the sheaf of papers he was studying and picked up the bottle of coke that had come with dinner instead. He'd wanted a beer, but he got the feeling he was going to need the caffeine. He took a long sip and regarded the papers ruefully. "I think working with Charlie has actually spoiled me in at least one sense."

"Oh?" Mac inquired, looking up from an array of transcripts.

"Since he started working with us, we pretty much hand anything like this," Don waved at the sea of paper, "off to him. He  _wants_  it. It's all data to him, more fodder for his calculations. We spend more time out chasing down witnesses and suspects and physical evidence than we did before because we don't need to worry so much about the paper trail."

Mac looked down at the papers he'd been studying and was quiet for a long moment. "Do you want to call him in after all?" he asked eventually.

Don leaned back against the foot of the bed and studied Mac for a long time. It was obvious that the other stallion didn't want Charlie in on the case. Don was certain he didn't have any real objections to Charlie--after all, they'd never met--or to Charlie's methods, since Mac was a scientist himself. Maybe it was about pride; Don knew from personal experience that watching Charlie solve in days a case that had stumped him for weeks was painful. But he didn't think so. It wasn't about Charlie. It was about sharing this case with anyone. After all, none of Mac's people were here with them, for all that they could have used the extra manpower.

"He could really speed this up for us," Don commented experimentally.

Mac didn't look at Don, just nodded and started gathering the papers before him into a stack.

 _He doesn't want to work with Charlie, but he'd do it if I told him to,_  Don realized. A little shock of...gratification went through him.  _He doesn't work for me, he doesn't owe me anything, but he'd obey. Because it's me._  Don could feel a strange sense of easiness sneak into him. For once one of his herd reacted the way they were  _supposed_  to!

He reached out and put his hand on Mac's arm, stopping him from gathering any more of the papers. "But anything Charlie can do can be done long distance." Don grinned suddenly. "It'll give us something to work on if we can't clear this thing while I'm here."

Mac glanced at him and smiled.  _He doesn't smile enough,_  Don thought. Which was a foolish thing to think, because Mac had been smiling plenty over the past two days, but Don got the sense that it was unusual. He had a good smile.

"I don't know about you," Mac said, breaking Don out of his thoughts, "but I've been staring at these papers for so long that I think I'd have them memorized even if I didn't have a perfect memory."

"Yeah," Don sighed, slowly lifting his hand from the solid curve of Mac's arm. "This is all beginning to seem a bit surreal. I keep having to remind myself how I got from the anthrax death of an INS agent in L.A. to the beating death of a gay college prof in New York."

"You think his being gay had anything to do with his death?" Mac asked, peering up at Don.

Don shrugged. "Probably not, but it could help account for the suddenness of the escalation. Beating someone to death is the kind of killing that usually involves a lot of strong emotion, and a lot of humans have powerful prejudices against that sort of thing."

"Mmmm. I sometimes wonder why more of them don't take a stallion's point of view on that," Mac commented. "A gay stallion is no threat."

"Depends on what it is you're worried about being threatened," Don pointed out. "For us, it's all about the herd. For humans...well, I'm sure you've run into more than one man who thinks a gay man is some sort of threat to his masculinity."

Mac nodded. "And then there's the religious objections," he said.

"Sometimes I'm glad we come with a different pantheon of gods," Don said wryly.

"And a rather hands on patron among them," Mac agreed. The two of them lifted their drinks in a toast, as if to an absent third party.

Mac shook head as he lowered his glass. "It's far too easy for me to forget that Zeus can be a real, tangible presence," he said, with the air of an admission.

"I know what you mean," Don said.

"But you're still in touch with your local herd," Mac asked, surprised.

Don shook his head. "Sure, I talk to them sometimes, but I was  _nine_  when I was fostered out. My dad and Charlie had way more of an influence on me than the centaur herd did." He paused, just thinking of his family for a moment. "My family is human. My people are human. I might feel like a herd stallion with them, I might...consider them mine, but that doesn't mean I interact with them the way a herd stallion does with his herd." Don smiled wryly. "It wouldn't work and I know it. I've had to work out different ways to take care of them."

"Do you ever miss being with other centaurs?"

"Up until I ran into Gibbs, I would have said no," Don began.

Mac blinked. "I thought you and he fought."

"We did," Don confirmed. "Although not until after being at each other's throats for two days. We scared half the audience out of the panels we had to sit on together. But after we settled things I..." Don hesitated.  _Maybe I shouldn't have brought this up,_  he realized. Mac had only given way to Don two days ago. Discussing a time when Don had handed over control to someone else might not be the wisest idea. But he'd brought it up now; the best he could do was to side step the issue. "I spent the night with him and his mate."

Mac's eyes sharpened with interest, but his question was casual. "His mate?"

Not the question Don had been expecting. "A human," Don said, watching Mac closely. "His lead field agent, actually, and an extraordinary man. He didn't have any problem at all with being owned by Gibbs, but he didn't let himself be walked all over, either."

"And these two made you want to be with other centaurs?" Mac asked skeptically.

"Sounds contradictory, I know," Don said wryly. "It wasn't who they were. It was how they were together. They understood each other completely. Tony responded to Gibbs exactly the way a dominant stallion would expect him to and he was completely comfortable with his own reactions. And the scent..." Don inhaled automatically, as if he could recapture that scent. He was momentarily surprised when his nostrils were filled with the warm, rich scent of another stallion. Mac. Don took another discreet breath before continuing. "I was an outsider with them. A guest. But it made me want what they had."

"And you don't think you can find a human who can give you that?" Mac asked. "Gibbs did."

"I've inflicted enough stories of my dating history on you that you ought to know better than me," Don said dryly. He sighed and shook his head, taking a swig of his drink and leaning back, resting his head against the foot of the room's queen size bed. "It's not like I haven't tried. I don't know, maybe if I was more aggressive it would work. But just running roughshod over people isn't my style. I don't have any trouble getting  _into_  a relationship, but once I'm there and I relax and try to let it develop, my reactions and their reactions are just...out of sync."

"You know you're not going to find any mares outside of the herd," Mac commented. His eyes rested on some of the papers spread out on the floor, though Don could tell he wasn't actually reading them.

"I know," Don said, watching Mac. "But my team knows I'm bi, even if I haven't dated any men recently."

"They do?" Mac asked, looking up, both his eyebrows raised.

Don nodded. "FBI policy on gay agents has improved a lot in the last ten years. I'm not saying it's never an issue, but the biggest official concern seems to be whether it'll have an impact on your security clearance. Being out at work and at home pretty much takes care of that."

"And unofficial concern?" Mac asked dryly.

"There are still bigots around," Don said, shrugging, "and they can still cause problems. But my team is with me, our AD is a good guy, and I've got an excellent record."

Mac hummed thoughtfully but didn't say anything else. Don found himself inhaling again, searching Mac's scent, but he smelled just the same. Which was really rather good. There was a chemical edge to it that Don recognized from the labs, but it wasn't unpleasant, just unique. Recognizable.

Don shook his head at himself.  _Not a productive train of thought._

***

Mac pulled into the hotel's lot, parked the car, and paused to take a deep breath. Two days and he still couldn't shake the unfounded anxiety that had been plaguing him. It had started when Don arrived, it had to be him, but it wasn't anything like the tense, aggressive confrontation of two stallions. Mac was more than familiar with that feeling after the past couple of days, and besides, Don didn't seem affected by it.

Sighing, Mac slid out of the car and headed into the hotel. In theory he could just call on his cell phone and have Don come down and meet him at the front desk, but it felt somehow appropriate to pick him up at his room instead. Besides, he'd probably need a hand with the boxes of documents Mac had left there the night before.

Arriving at the room, he knocked on the door and waited. And waited. He checked his watch. 8:15am. He knocked again. After a long moment, the door opened to reveal Don in a dress shirt and pants, but no shoes, socks, or tie. He was still rubbing at his hair, which was damp, with a towel.

"Sorry," he said, smiling sheepishly. "I got a later start than I expected. Come on in."

Mac stepped into the hotel room and found himself running his eyes over Don again. Slower. Even last night, sitting on the floor amid student transcripts and class lists, tie completely discarded, he'd seemed very...put together. This morning he hadn't quite settled into his professional skin yet. That, even more than dinner the night before or drinks the night before that, brought home to Mac that this man--no, this  _stallion_ \--was the same person he'd been chatting with on the phone for eight months.

Who was really quite attractive.

Mac fought down a traitorous warmth. The  _last_  thing he needed was for Don to catch a whiff of arousal off of him. It didn't matter that Don was bisexual. It didn't even matter that Mac belonged to him. The last thing Mac wanted to do was spoil this friendship by bringing sex into it.

If that thought left him feeling a little hollow, a little shaky, well, he ought to get used to it. Don had less than twenty-four hours left in New York.

"We should probably do a little planning before we start on the interviews," Don said as he tied his tie. "We've got eighteen people to talk to--" there had been twenty-seven on the class list, but nine of them had moved out of state "--and they're spread all over the city."

Mac nodded. "We can use my office. I should check in at the lab, anyway."

Don shot him a look. "Should I prepare myself for Detective Flack again?" he asked dryly.

"I think he's wise enough to steer clear," Mac said, smiling a little.

"You never know," Don said, shaking his head. He sat down on the end of the bed to pull on his shoes and socks. "We've thoroughly trashed the status quo you and he had going. He's going to want to know where he stands and he's not going to be shy about it." Don finished with his shoes and socks, watching Mac carefully as he shrugged into his suit jacket. "There's every chance he'll consider your team up for grabs, so to speak."

Mac frowned, pausing to let Don leave the hotel room before speaking. "Flack isn't a CSI," he commented, pulling the room's door closed behind him. "And we're hardly the only team he works with."

"He works with you more often than anyone else," Don pointed out. "And his association with you, as a centaur, will have predisposed him to thinking of them as a herd, a group of people that  _needs_  an owner. It doesn't matter that he knows they're human; instinct doesn't always listen to logic."

Well, at least Flack would take good care of them. If it came to that, of course. Mac shook his head, but didn't answer Don's worried look.

***

The two of them had been in Mac's office for barely 45 minutes when Flack appeared. Mac glanced over at Don, shaking his head wryly, before setting aside the map he'd been marking addresses on. "Can I do something for you, Flack?"

"I need to talk to you. Alone," Flack said, pointedly not looking at Don.

Mac did glance over at Don, though he didn't intend it to be pointed and hoped Flack wouldn't take it that way. Don nodded slightly and Mac rose and came around his desk. He and Flack stepped out of the office and walked down the hall a ways and into an empty lab.

"I thought we were going to avoid each other until Don went home," Mac said.

"I don't take orders from Stella."

"News to me," Mac said dryly. He'd witnessed Stella sending Flack jumping on numerous occasions.

Flack clenched his jaw and blew out a frustrated breath. "She was practically your lead mare, Mac," he said. "Besides which, it was pretty clear you expected me to give your people a long leash."

"And now what?" Mac asked, raising an eyebrow. "You're going to start ordering  _them_ around? That'll go over well. Especially with Stella."

"'Now what' is exactly what I'm trying to figure out!" Flack turned his back on Mac and took two steps away before turning and stalking back up to him. "I'm trying to figure out why you'd roll over for a stallion who isn't even local without even  _trying_  to put a fight."

"I haven't rolled over for him," Mac said sharply.

Flack froze. "I was speaking metaphorically, Mac," he said sardonically.

 _Oh._  "As for why," Mac said evenly, "it's not like Don is a stranger to me." He paused, trying to gather his thoughts into some kind of logical framework. "I didn't  _want_  to fight him," he said eventually. "Don is a good man and a good leader. It's his case, it always has been. I've been supporting him on this for eight months."

"On this," Flack pointed out. "But according to Eppes, this isn't a temporary arrangement. Did you even think of how this would impact your people?"

Mac frowned. "I've always tried very hard to treat the people I supervise the way a human would," he said. "I'm not always successful, but I put real effort into  _not_  thinking about them as if I owned them."

Flack actually laughed for a moment. "Damn. No wonder you blow so hot and cold on them sometimes."

"Has someone complained to you?" Mac asked eyes narrowing.

"Why should you care? They aren't yours."

"Not owning them doesn't mean I'm not responsible for them," Mac shot back. "I'm their boss."

"And if one of them  _did_  complain to me?" Flack asked smoothly.

Now it was clear where this was going. "I may not be over you anymore," Mac said, "but you aren't over me, either, Flack. Quit taking pot shots at my authority. I'm not any more interested in fighting you now than I was when we first met."

"Listen, I like you, Mac," Flack said bluntly. "I'd rather not fight you. But your team deserves to be properly taken care of, and you've made it pretty clear that your priority is a stallion who doesn't even live on the same side of the country, never mind the same city, or state. I'm more than willing to step in."

Mac resisted the urge to rub his forehead. "You think it'll be that easy? Administrative structure in the lab means they'll still be taking their professional direction from me, regardless of how things stand between us, and I doubt any of them would take well to you stepping in to manage their lives."

"I didn't say it would be easy," Flack said evenly. "I said they deserved it. And if you think managing lives is what's involved in taking care of a herd, then it's suddenly a lot clearer why you apparently never really tried, never mind succeeded."

"Regardless of how this works out," Mac snapped, "I think I deserve a little more respect than that."

Flack paused and tilted his head a little. "All right, fair enough." He didn't apologize, Mac noted.

"I have a case to work," Mac said briskly, "and not much time left to do it in. We'll have to pick this up again later." He turned away from Flack and headed for the hallway.

"Mac," Flack called out. Mac paused in the doorway from the lab and turned back. "Just because you're putting this on hold while Eppes is here," Flack said, "don't expect me to do the same." Mac nodded and left the lab where they'd been speaking, heading back to his office and Don.

"Everything okay?" Don asked as Mac closed his office door behind him.

"That depends on your definition of 'okay.'" Mac sat down at his desk and returned his attention to mapping out the order of the former students they'd be questioning that day. "Let's just say you were right about Flack's perception of the team."

"Hey," Don said, turning away from his work. He laid his hand on Mac's back, a warm, solid presence. "I know you consider Flack a friend. This can't be easy."

"This case is my priority right now," Mac said, fixing his gaze on the map he'd been marking. "Flack can wait a day."

Don was quiet for a moment. "If you want to hang onto your team, maybe not," he said, but nodded at Mac's computer, which he was using, and switched conversational tracks without waiting for an answer. "I've got a pretty good idea of the tack I want to take with these people. How're you doing over there?"

Mac had almost been done when Flack interrupted them. "Give me ten minutes and we can head out."

***

Don couldn't help frowning as he strode down the hall of an apartment building to their next interview. Twelve down, six to go, and there was  _still_  something about the fifth person they'd talked to that was nagging at him. He hadn't really said anything different than the rest had--almost all of the people they'd spoken to had trouble recalling the  _class,_  never mind who'd taught it, although most of them remembered the fact of the murder once Davies's name was mentioned--but Don was stuck on him like a CD on repeat.

"Don," Mac said quietly as Don reached out to knock on the door. Don paused, glancing over at him inquiringly. "I think a more neutral expression would be useful here."

Grimacing briefly at his own inattention, Don smoothed out his expression. "Thanks," he said.

"I take it the Lake interview is still bothering you," Mac commented.

"Yeah," Don said, rapping firmly on the door. "Something about that guy rubbed me the wrong way, but I can't figure it out. It wasn't anything he said, or the way he smelled, but the longer we talked to him, the more suspicious I felt."

"Maybe we should take a closer look at him when we're done today," Mac suggested.

Don grimaced. "That may be all we  _can_  do. Today is my last day in New York. I have to fly out tomorrow morning."

Mac frowned, too. "Damn," he muttered.

Just then the door opened, revealing a young man dressed in jogging gear. A little odd, for a Friday morning, but it was entirely possible he was taking a long weekend. "Can I help you?" he asked, warily.

 _Did no one ever knock on this guy's door?_  Don produced his ID. "Special Agent Eppes, FBI. Can we talk for a few minutes?"

The guy--David Pennant, if their information was correct--didn't answer, instead turning his attention to Mac. "And you are?"

Mac already had his badge out. "Detective Taylor, NYPD CSU. I'm assisting Special Agent Eppes in his investigation." Pennant paused. "May we come in?" Mac asked pointedly.

Pennant hesitated before stepping back from his doorway. "Yeah, sorry," he said, standing to the side to let them into his apartment. Don glanced around as he entered. It was a decent place, but not anything extravagant. Then again, Pennant was a legal secretary, not a lawyer. He'd gone to law school, but he hadn't done too well, and had never passed the bar.

The door shut behind them and Pennant circled around Mac to stand in front of Don in his living room. He didn't sit and he didn't invite them to do so, either. "You said you had some questions," he prompted.

"We're investigating a cold case from 1996," Don began. "The murder of Robert Davies and his partner, Evander Stefanos."

"That's a little out of FBI jurisdiction, isn't it?" Pennant asked, folding his arms across his chest.

Don was careful to keep his expression neutral. "It's in connection with the death of a federal agent in Los Angeles."

Out of the corner of his eye Don could see Mac shift his weight, but that was the only indication of his surprise at Don's shift away from the set of questions he'd been working off of all morning.

The digression itself paid off; something definitely changed in Pennant's wary expression. "A home invasion in New York and a murdered federal agent in L.A.? That's a little far fetched."

"We didn't say he'd been murdered," Mac observed, forcing Pennant's attention to shift. "Just that it was in connection with his death."

"What do you know about Robert Davies' murder?" Don asked, jerking Pennant's attention back to him.

"Nothing!" Pennant snapped.

"Nothing?" Don asked, raising his eyebrows. "You took History 409 from him in your senior year. I think I'd remember something if one of my profs had been murdered."

" _That's_  why you're talking to me?" Pennant asked incredulously. "Because I took a class from him? There must have been thirty people in that class. You planning on talking to all of them?"

Don did a quick mental evaluation before shrugging and saying, casually, "Twenty-seven, actually, and yes. You're number thirteen."

Pennant visibly relaxed. "Lucky number thirteen, huh?" he snorted. "Listen, I don't know what you expect to get out of this exercise. Professor Davies was killed in a home invasion. The case is closed."

"I thought you didn't know anything about his murder?" Mac asked.

"And, technically, the case isn't closed if a suspect was never arrested," Don said before Pennant could respond.

"Right," Pennant said. "Listen, I'm sorry, but I can't help you. Are we done here? I'd like to go out for my run."

"Of course." Don turned and headed back out of the apartment. "Sorry to have kept you."

Pennant followed them out of his apartment, heading for the stairwell while Don and Mac waited for the elevator. Whether he preferred the stairs for fitness or was just eager to get away from them, Don wasn't sure.

"Any particular reason you decided not to bring him down to the station for questioning?" Mac asked when Pennant had been gone a few seconds. "He was jumpy as hell."

Don glanced at Mac. "I want to figure out what it is about Lake that bothered me, first," he said. "I had a bit of that same feeling when Pennant opened the door, before he set off every red flag I have."

"Even a couple of hours is going to make him more difficult to interrogate."

"And I don't have time to spend chasing down whatever false leads he hands us while he stalls for a lawyer," Don replied. "I need to go in there with as much information as possible."

The elevator arrived with a soft  _ding_  and the doors slid open. "So we pick him up and let him sweat while you work it out. I think we could break him--"

"Mac," Don said firmly, blocking the elevator door with one hand but not stepping inside yet. "Stop." Mac stopped, and Don had to resist the urge to blink in surprise. "Yeah, the guy was jumpy. Yeah, maybe we could get something out of him at the station. But we don't even know what we're fishing for right now, and we don't have any hard evidence to wave at this guy to keep him on his toes. I don't want him to know how little we know and I really don't want to tip our hand, given that there were  _two_  sets of prints unaccounted for in Davies and Stefanos's apartment. With patience and some legwork we can go in there a lot better prepared."

Mac stared at him for a moment, nostrils flaring a little, and then he nodded sharply. "Sorry."

Don waited a moment, studying Mac, and then nodded back and stepped into the elevator, letting the door go and hitting the button for the ground floor. "You always move that fast on your cases?"

"Not always," Mac said, although there was a hint of wryness to his tone. "But once we have our eye on someone we're more likely to bring them in and press them than wait."

"I've got a weird feeling about these two." Don frowned again. "I  _know_  I could get further with them if I could just pin it down."

"You want to skip the rest of the interviews?" Mac asked. "See if you can figure it out?"

Don considered that for a moment. It was tempting. Very tempting. But if the interviews didn't pan out, this was something he could probably work out without physically being in the city, if he had to. He glanced over at Mac and had to suppress a sigh. "No," he said aloud. "Two of them have tweaked me so far. Let's see if anyone else raises flags."

***

No one else did.

"Well, that was a waste of time," Don muttered as they walked down the steps from the last interviewee's residence.

"There was no way to know without doing it," Mac said, shrugging.

Don glanced over at Mac and found himself laughing. It wasn't that there was anything  _funny_ about the moment, really. It was more that Mac was calm and philosophical about something he hadn't wanted to do in the first place. "I'm glad I'm doing this with you, Mac," Don said, still chuckling as Mac shot him a confused look.

"Because I've been so very useful so far," Mac said dryly. "I haven't done anything you couldn't have done on your own."

Don could feel his eyebrows rising. "Aside from pushing me to go through twelve boxes of evidence and then volunteering to help? I'd never have found that letter in a case report, Mac. It was logged as blood evidence, but it was the handwriting I recognized."

"And since then I've played tour guide," Mac commented. His tone was calm and he seemed relaxed as they climbed into the car, Mac on the driver's side, but his words made Don wonder.

Where was this coming from? Mac had never sounded uncertain like this when they'd talked about his cases...  _Ah. It's probably been a long time since he wasn't the lead, even when he worked with other detectives._  Don remembered how Colby and David had been when they first started with him: both experienced agents, but not in the FBI and not with him, they'd each taken some time to find their feet. And neither of them were centaurs.

With Colby and David, Don had just given it time. Mac...Don wanted Mac to be comfortable.

Don leaned back in his seat and watched while Mac started up the car and pulled into traffic. "I don't know this city and I don't know people's attitudes here," he said. "L.A. has a slightly different vibe, so I hope you'll excuse me for needing a tour guide."

Mac snorted, but the atmosphere eased. "So what's next on the schedule?"

"Dinner," Don said emphatically. "I'm starved and the low blood sugar isn't helping with the nagging feeling that I'm  _this close_  to connecting the dots on Lake and Pennant."

"Pizza okay?" Mac asked. "I know a place."

"Sounds good," Don said. He smiled suddenly. "Besides, David would never respect me again if I gave up a chance at decent pizza."

Mac shot him a curious glance. "Decent pizza?"

"According to David and Megan, the first thing you learn when you get to L.A. is that there's no good pizza," Don answered.

"I've never been to L.A.," Mac commented, "but I can tell you I've never had pizza better than this place makes it."

Don kept the conversation away from work as they drove, but he couldn't stop his mind from worrying at the nagging feeling that he was  _missing_  something about Lake and Pennant. If it had been just Pennant, he could have put it down to the guilty-as-hell way the man had behaved, but Don had gotten twitchy over Lake first and  _he_  hadn't done or said anything Don would normally have been suspicious of.

Don was confident that his feeling about Lake had something to do with Davies's and Stefanos's murders, but Pennant's guilty conscience could be the result of a much more recent transgression. Although, really, that was unlikely; he'd still been nervous after he knew what they were looking into. He'd only calmed down once Don had told him they were questioning everyone in the class and he'd realized they weren't specifically after him.

Part of Don's mind registered that they'd arrived at the restaurant and followed Mac inside even as he worried over the case. The problem was, it didn't make sense for Pennant to be worried  _before_  Don had told him they were investigating the Davies/Stefanos murders. Even if he was the killer, ten years was more than enough time for Pennant to grow comfortable with the assumption that he'd never be caught. He should have been relaxed, even when the FBI showed up on his doorstep.  _Especially_  when it was the FBI who appeared, actually, because there was no reason for Pennant to think of a pair of New York murders when he ran into the FBI. It was like he'd been expecting to be questioned about the case.

Don froze, a glass of water halfway to his lips. "Lake called Pennant," he said aloud.

Across the table, Mac looked up from the menu, brow momentarily furrowed before he shook his head and smiled a little. "You've been somewhere else completely for the past half hour, haven't you?"

Don smiled sheepishly and set down the glass of water. "Ten years on this case," he said, shrugging.

Mac nodded, but before he could say anything, their waiter arrived. Don looked down at his menu, suddenly aware that he hadn't so much as glanced at it. He looked up to find Mac watching him, amused. Don smiled mischievously. "You know the place. You order."

Mac shook his head a little, but did as he was told, leaving Don free to watch him for a moment. His voice was nicer in person than it was over the phone, Don decided, and it suited him. He wasn't built, but he was comfortably solid. His expression had a tendency to settle into intent, thoughtful lines. Mac was the sort of man that was described as handsome instead of pretty.

"What makes you think Lake called Pennant?" Mac asked as the waiter stepped away from their table, his face settling into those intent lines again.

Don yanked his thoughts back to business. "It explains why Pennant was so nervous when we got there," he said. "After ten years, why would the FBI, of all people, come asking him about Davies? But he was jumpy from the get go. Say he and Lake were in it together ten years ago. After we talked to Lake, he could have called Pennant to give him a heads up."

"It doesn't explain why Lake put your back up to begin with," Mac pointed out.

"I know." Don frowned. "I still can't figure that out."

"Something from the case files?" Mac suggested. "He was questioned before."

"Not by me," Don said, and paused. "Case notes alone wouldn't trip my instincts," he said, but his attention wasn't on the words. Something was wrong with what he'd said.

 _He was questioned before._

 _Not by me._

 _Lake...Pennant...questioned by me..._

Don's eyes widened. "Holy shit!" he exclaimed. Heads swiveled in the restaurant to look at him, but Don ignored them, leaning across the table towards Mac. "I  _have_  questioned them!"

"Lake and Pennant?" Mac asked, startled.

Don nodded emphatically. "In L.A., ten years ago, after Carlos Esteban was killed."

"I thought we were thinking of them for Davies and Stefanos."

"We are," Don agreed. " _And_  Esteban."

"The murders were a couple of days apart," Mac mused. "But Pennant couldn't afford to jump on a plane on such short notice."

"Lake could," Don said, warming to the idea. "I don't know why they went to L.A., but they had the means to get there."

Mac was frowning thoughtfully. "The postmark on the Davies letter," he said slowly, "it was more than a week before his and Stefanos's death."

Don nodded. "I remember. I thought for a second that I'd been wrong about the suspicious timing when I realized that Esteban's letter had been forwarded across the country and arrived later than the killer thought it should have."

"And Davies's letter arrived, but apparently was never opened," Mac said. "Lake and Pennant didn't want either Esteban or Davies dead, but he wanted Davies, at least, scared. So he mails off a threatening letter, dosed with anthrax to give the threat more weight." Mac paused and frowned. "But why bother to send a second one to Esteban? There was no threat in that one."

"A guarantee, maybe?" Don guessed. "To double check that the anthrax worked?"

"Or camouflage," Mac suggested. "To make it look like a random attack."

"The note kind of defeats that purpose," Don said dryly.

"Only if Davies reported it. If the threat worked, he wouldn't have."

Don pursed his lips thoughtfully. "Hmm. Well, whatever the reason, nothing happens to either guy."

"Which worries Lake and Pennant, because one letter might go astray or unnoticed, but two?" Mac continued.

"They want to know what's going on," Don continued, thinking aloud. "They look into it and realize that the guy who was supposed to get the other letter doesn't even live in New York anymore, and an anthrax letter in L.A. from New York is going to attract a lot closer investigation than one inside the state..."

"So they rush to L.A. to intercept it," Mac continued.

"And arrive just in time to show up at the scene of the murder and be questioned by a rookie FBI agent," Don said. "That's a hell of a coincidence."

"So is Esteban just so happening to be Evander Stefanos's INS guy," Mac said wryly, "given that Stefanos had nothing at all to do with the motives for this murder."

"Fate finally tossed me a break on this case," Don said. He grinned. "After all this time, I think she owed me one."

"Fate wasn't the only one who gave you a break," Mac said, smiling a little.

"Would you be referring to a guy with a dozen boxes of evidence in his office and a penchant for working too much?" Don said, grinning wider.

"I'm not the only one who works too much."

"No argument there." Don's mind wandered back to his reason for working too much this time. "We still don't have motive."

"That, we can get in interrogation," Mac said confidently. "I assume you'll want to bring them in, now that you've figured out what was nagging at you."

"Oh yeah," Don said emphatically. Their waiter arrived and set down dinner in front of them.

Mac looked at the two gooey-hot pizzas and sighed. "We're going to have to have this boxed up, aren't we?"

Don opened his mouth to say yes, but paused momentarily as a thought struck him. Mac had been even more eager to bring Lake and Pennant in than he had. So why the hesitation? Because the case was almost closed. Don was going home in the morning. This was the last meal they'd have together. "Nah," he said instead. Mac raised his eyebrow and Don shrugged. "They've been waiting all day. They can wait another hour."

"They'll be easier to interrogate if they're still hungry when we bring them in," Mac argued.

"It'll take us at least 40 minutes to organize a couple of squad cars to meet us to pick them both up," Don said. "And it's already past six. They'll probably have eaten by the time we get to them if we start now."

Mac frowned, but conceded with a slight nod. He hadn't really put up much of a fight. Don smiled internally and steered conversation onto other topics.

***

Although it was Don's case, he let Mac and the uniformed officers take point when they went to bring Lake and Pennant in for questioning. They weren't under arrest yet; there was plenty of solid evidence, but nothing but instinct and speculation linked any of it to the two men at this point. And it was more diplomatic to let New York officers handle New York citizens. Especially when the federal connection was still so tenuous.

They managed to catch Lake off guard, and sent him to the station in one of the squad cars while the rest of them headed over to pick up Pennant. Don arranged for a couple of uniforms to cover the building's exits and headed into the lobby with Mac and another pair of officers. They didn't even reach the elevator before one of the uniform's radios crackled to life.

"He must have seen us pull up," a staticky voice announced breathlessly, "'cause I spotted him bolting out the back exit before I could cover it. He's headed west on foot."

Don spun and ran back across the lobby, Mac and both uniforms following, rather than try to find the back exit. He piled on the speed, painfully aware of the lead that Pennant had on him. As he rounded the building and turned west into the alley, he realized he was leaving the uniforms behind.  _Shit!_  Out running his own back up was not a good idea, not when he was chasing down a nervous, scared suspected murderer. Don glanced back a little to judge how much he'd have to slow down...

...and found Mac right on his heels.

Grinning fiercely, Don jerked his head in the direction of the chase-- _Stay with me!_ \--and pushed himself  _harder_. Focusing forward again, he caught sight of the dark blue flash of the uniform who'd gone after Pennant when he'd spotted him take off down the alley. Don was gaining on them, drawing steadily closer. The sight was like a goad; he wasn't too surprised when Mac put out an extra burst of effort and pulled up to run at his shoulder.

For once, Don's legs burned with the effort of running at top speed. When they passed the last uniform he traded a grin with Mac and had to resist the urge to whoop in triumph as they caught sight of Pennant less than a block ahead of them. The wind rushed by them, a faint suggestion of what it was like to race across a field in his other shape, and Don found himself trying to lengthen his stride again.

Don caught up with Pennant few steps before Mac and tackled the man to the ground. The two of them rolled across the asphalt of the alley, but despite the catching up Don had had to do, Pennant was gasping for breath twice as hard. He lay there panting and didn't resist as Don cuffed him.

Mac was waiting when Don looked up. Waiting and smiling broadly. "Were you racing him or me?" he asked when Don hauled Pennant to his feet.

Don laughed. "Racing the wind," he said, grinning.

"I think the wind lost," Mac said, eyes twinkling, and took one of Pennant's elbows to help lead him back to the squad cars.

***

They were watching Pennant from one of the observation rooms when there was a quiet knock on the door. Silently, Don prayed it wasn't Flack choosing this moment to poke at Mac a little more. The station was, in a sense, his territory, which would give him a definite advantage, but Don hoped he'd be professional enough not to put an interrogation at risk.

The door opened and Tom Masters poked his head in. Don breathed a silent sigh of relief. "Hey, you guys got a minute? I have something."

Mac gestured for him to come in. "He can wait a little longer," he said.

Masters stepped into the observation room and closed the door behind himself. "I got the DNA profile back on that anthrax strain."

Don turned his full attention on the tech. "Did you get in touch with L.A.?"  _Assuming my office managed to dig up the sample and run it._

"Yeah," Masters said, grinning. "They match."

"Excellent." Don smiled. "Another nail in the coffin."

"Thanks, Tom," Mac said, clapping the man on the shoulder before he ducked back out of the observation room.

"Pennant first?" Mac asked, but his tone made it more of a confirmation than a real question.

Don nodded anyway. They had Lake in a separate interrogation room and Pennant had been jumpier to begin with anyway. "We'll go in together," he said.

Mac nodded and followed Don out of observation and into the interrogation room. Pennant's head jerked toward the door as they stepped into the room. There was, Don thought, something almost like relief in his eyes, for all the stubborn set to his jaw.

"Mr. Pennant," Don said casually, dropping a file on the table and sitting down in the chair across from him. "Sorry to interrupt your day again. You want something to drink? Eat? We haven't got much, but there's a candy machine if you're hungry. You certainly used up a lot of energy earlier."

"No, thank you," Pennant said, flushing in embarrassment and taking a quick breath. His eyes darted briefly to the wall behind Don's shoulder, where Mac was leaning quietly. "I've had dinner."

"Yeah?" Don said, smiling a little. "You order in or you cook?"

Pennant's eyes flickered and a faint line of confusion appeared between his eyes, but he answered. "I ordered in. Italian."

"Hey, that's weird," Don said, affecting surprise. "I had Italian myself. I went out, though. Got to take advantage of traveling on the company dime." This time when Don smiled, Pennant smiled back, but shifted uneasily in his chair. "I'm from L.A.," Don went on, "so there's good Mexican food, but not so much with the Italian."

"Right," Pennant said. "Listen, I, uh, appreciate the consideration, but I'm pretty sure I'm not here for a discussion of the city's cuisine."

"Yeah, you're right, I'm sorry," Don said, smiling again. "You remember we were talking to you about Evander Stefanos and Robert Davies this afternoon, right?"

Pennant nodded. "And I told you I remembered he'd been killed in a home invasion the year I was taking his class. I thought that was it."

"Well, that's the thing," Don said. "We did a little extra checking on you and it looks like you're a little more involved than that."

"Involved?" Pennant asked, his voice rising just a bit. "Involved in what?"

"In three murders," Don said flatly. "Robert Davies, your primary target. Evander Stefanos, his partner. And Carlos Esteban."

"I don't--"

Don cut Pennant off before he could finish. "Then why'd you run? I gotta tell you, that makes you look guilty as hell. You might want to get a lawyer in here."

"I don't need a lawyer," Pennant snapped. "I'm not an idiot. I went to law school, I know my rights. I  _also_  know that if this wasn't a wild goose chase you'd have arrested me."

Somehow, Don wasn't surprised this guy hadn't actually passed the bar.

"You wanted Davies dead," Don said, ignoring Pennant's comment. "Stefanos was in the wrong place at the wrong time. But you know what  _really_  burns me?" Don asked, his voice growing steadily louder. "Carlos Esteban. He was just  _camouflage._  He wasn't even successful camouflage. You fucked up the anthrax letters so badly--and it astounds me that you managed to put those letters together, but couldn't  _mail_  them correctly--that you missed your main target completely and killed an innocent man a couple thousand miles away from your target area."

Pennant was looking flushed. "I don't even know who--"

"Don't play stupid with me," Don interrupted again. "You knew Carlos Esteban. You were at the scene when he was killed." Don cocked his head and smiled a hard smile. "You might not have a very good memory, Mr. Pennant, but my memory is  _excellent_. I worked Esteban's murder scene in L.A. ten years ago. He was an INS agent, you know. Federal jurisdiction. I was just a rookie at the time, so I got one of the scut jobs--interviewing everyone who showed up at the scene, looking for witnesses. You were just a college kid then, but it was definitely you."

Don spotted a drop of sweat forming at Pennant's temple. Time to really start pushing. "I can see what happened," he said confidently. "You were in Davies's class. He was pushing all of you hard, harder than most of the undergraduate professors because he cared more about his classes than his research. You were feeling persecuted and you weren't doing very well. In fact," Don went on, moving into speculation based on the note, the fact that Davies had spoken to the department head about the midterms, and the comment Sanders had relayed about students 'earning their grades,' "you were failing. You knew you had to pull your fat out of the fire if you wanted to get into law school, so you came up with a plan."

Pennant's eyes widened just a bit. "My grades weren't  _that_  bad," he protested.

"I've got your transcripts, Mr. Pennant," Don said, flipping the folder open and turning it towards Pennant so that he could see for himself. "Your grades were very uneven. You'd start off slow, with dangerously low grades. You almost failed more than a couple of classes. That's not good enough for law school. You needed to do better. Hence the plan." The sweat was running down Pennant's face now. Don had no idea what the plan had been, but he was sure there had been one, now. Probably one that could have resulted in expulsion, given the lengths Pennant and Lake had gone to keep it quiet.

"And for a while, you thought your plan was working. But Davies was a smart guy. He picked up on the sudden change. He started poking his nose into places it wasn't wanted," Don said, intentionally quoting the anthrax letter. Pennant tensed minutely at the wording. Don paused, partly to let Pennant sweat, partly to make sure he had the timeline right in his head. "You needed him out of the way, but you couldn't let anyone take too close a look at him, because they'd follow the evidence straight to you. So you decided to spread the attack around a little. Make it look like a terrorist, or a bunch of crazies. Anthrax attacks were well known around that time. You picked a couple of random people to divert suspicious. Collateral damage." Don didn't actually know of anyone other than Esteban who'd been afflicted with anthrax within the right time frame, but it made sense. One extra victim wasn't much of a smokescreen. He made a mental note to check the FBI database when he got back to L.A., just in case these two had been responsible for any other deaths.

"One of the letters made it to Davies's apartment," Don went on, "but for some reason he didn't open it. The recipient of another turned out to have moved out of the state. But you didn't know that. A week went by and nothing happened. Davies didn't back off, there were no reports of anthrax exposure. You had to be wondering what the hell happened. And Davies was getting closer. You had to try again. You had to make sure this time."

"I didn't--"

"So you went in person," Don overrode his objection. "You took care of it yourself. You beat him to death with a baseball bat." Don stood and leaned over the table at Pennant. "You must have been angry as hell, and scared on top of it, because you made a hell of a mess. And when Evander Stefanos walked into the room, well," Don raised his voice a little, "you couldn't leave a witness. What was one more body piling up?"

"I didn't do it! I wasn't there!" Pennant shouted.

"Then prove it," Mac said, so quietly, such a contrast to Don, that the entire focus of the interrogation snapped immediately to him. "It's easy," Mac went on casually. "The killer left blood and hair and fingerprints all over that apartment. He wasn't very careful. Give us fingerprints and DNA and you're off the hook."

Pennant blanched. "I don't have to prove anything to you," he said, his voice on the edge of trembling.

Don didn't turn away from Pennant, but the sound of clothing rustling told him that Mac was shrugging. "Suit yourself," he said. "Special Agent Eppes's recollection of you was enough to get a warrant for your apartment. Between the handwriting samples and fingerprints we pick up there, we'll have a court order for your fingerprints and DNA soon enough. I just thought you'd like the opportunity to do yourself a favor by cooperating."

They hadn't actually had time to get such a warrant, never mind send a team over to Pennant's apartment, but he didn't know that, and the way he'd paled was confirmation enough that his DNA would match. "Give me a little credit," Don said confidently, leaning back in his chair. "I've been doing this for better than ten years. Do you think I would have come in here unprepared?"

Pennant started to speak, but Mac beat him to it. "The evidence is stacking up against you, Mr. Pennant." His tone was calm, inexorable. "You left a mess at the scene. The only thing protecting you was your lack of motive, but we've got that now."

Don leaned forward again, resting one forearm on the table and speaking in an understanding tone. "Listen, I understand," he said. "I mean, your career was on the line. Your whole life. If you didn't do well in this course you'd never get into law school, never get to live your dream. You tried to reason with the guy, but he just wouldn't  _listen_. You had to do something."

"I still had a chance, then," Pennant muttered. "I was going to make something of myself."

"It was all slipping away," Don said quietly. "You had to do something. Professor Davies was all that was standing in your way. Get rid of him..."

"It wasn't like that!" Pennant snapped.

Don shifted tack slightly. "It wasn't about hurting anyone. It was just the..." Don hesitated, as if uncertain.

"Just the marks," Pennant filled in. "We just wanted better marks. We figured out how to do it, too."

Don took the comment and worked with it. "Everyone knows university is about working the system, getting the right things down on paper," he said. "No one remembers much from their classes. It's about the piece of paper, not how you get there. You didn't work the system like everyone else did; you were smarter than that, more creative."

"It worked beautifully," Pennant said, almost absently. "Eighteen different people, four classes, four different professors. That wasn't easy to set up, you know."

"And Davies was going to ruin it all."

"We didn't want to kill him," Pennant said sharply.

"Nah," Don agreed. "You just wanted him to back off, leave you alone. He had hundreds of students. Why shouldn't he let a couple of you go?"

"None of the other professors paid more attention to their courses than they had to," Pennant commented.

"But Davies was always poking around in his students' business," Don said sympathetically.

"He was a complete micro-manager," Pennant agreed. "We just wanted him to back off a little."

"It was an accident," Don said, guessing. "No one was supposed to get hurt. You were careful."

"We even had a girl in Bio pick the strain," Pennant said, and Don's attention sharpened. The anthrax. "She said it would just make them a little sick. No one would even need to be hospitalized."

"You didn't know Carlos Esteban had a compromised immune system," Don inserted. "You can't be blamed for that."

"We picked him out of the  _phone book_ ," Pennant said. "What kind of shitty luck is that?"

"Must have scared the hell out of you when he turned up dead," Don suggested. "Waiting and waiting for the letters to arrive and nothing is happening, and then suddenly you've got a dead body on your hands."

"We didn't mean to hurt him," Pennant insisted. "Hell, we even tried to intercept the letter when we figured out what had happened to it! But when we got there..."

"And Davies was still poking around. He'd made you kill someone, and he was still screwing you over. You were scared and angry and everything was on the line. If he'd just backed off, left you alone, it would have been fine."

"It  _would_  have been," Pennant said intently. "We tried everything, but that guy died and then everyone starts talking about how someone had agreed to talk to Professor Davies about some big cheating ring..."

The mysterious appointment! Don had to work to conceal his excitement, instead pushing the theme. "And that only made him worse. He pushed harder. Pushed and pushed and you had to fight back. He was going to destroy  _your_  life."

Pennant was leaning over the table now. "You understand," he said. "I didn't have a  _choice_. My whole life was on the line. I just wanted him to back off."

"So you went to his apartment," Don prompted.

"Just to scare him a little," Pennant agreed.

"But, like always, he had to push."

"He never knew when to stop, when to back off."

"You reacted," Don said. "But he had to fight you."

Pennant nodded. "He always did."

"But you wouldn't let him win this time. It was your life," Don suggested.

"I had to defend myself," Pennant said intently. "It got...intense. I didn't know his partner was going to be there. I was surprised. Off balance."

"You didn't mean to kill him," Don said softly.

"No," Pennant said.

From the corner, Mac's voice quiet and certain: "But you did."

"Yes," Pennant said. He took a deep breath and shuddered. "He was going to destroy me. I tried everything, but he was going to destroy me. I had to kill him."

Don stood and left the room without another word. Mac followed him, carefully closing the interrogation room door behind them. "We'll have to find the girl who supplied the anthrax," Don said quietly. "She's an accessory, and with that lack of regard for security, who knows what she's been up to for the last ten years."

"Hopefully she was just being a stupid kid," Mac said. "But with Pennant's confession in hand, Lake will probably give her up for a reduced sentence."

"If Pennant doesn't beat him to the punch," Don said dryly. He had to shake his head. "Hard to believe this entire case came down to a couple of college undergrads who wanted better grades," he commented.

"I find that there are very few murders that are driven by worthy motives, if there is such a thing," Mac said. "I imagine on your level people are driven by bigger issues, but most crimes are...petty, when you get right down to it."

"Believe me, even on the Federal level there are plenty of petty motives," Don said wryly. "But yeah, probably fewer of them."

Mac tilted his head towards the other interrogation room. "We better get Lake taken care of."

Don nodded. "Time to finish this."

Lake's lawyer was already with him by the time they got there, which just proved that he was smarter than Pennant, even if the gesture was futile at this point. Don and Mac stayed just long enough to impress upon him how truly screwed he was before placing both men under arrest and having them transferred to holding.

Don suspected New York would end up with final jurisdiction over the case, given that Esteban's death was collateral to the primary target. After ten years, he was too glad to have the case closed to care where it was tried. Anyway, it was the lawyers' problem now. All that was left for him and Mac was paperwork...but that could be done long distance.

Standing outside the station in the cool night air, Don glanced quickly at his watch. "Twenty after eleven," he said, sighing.

"You probably want to get back to your hotel," Mac said, subdued.

Don knew he  _should_. His flight was at 10:00am the next morning, which meant he had to be at the airport around 8:00am, to be safe, but...he'd just closed a ten year old cold case. "Yeah," he said, watching as Mac nodded slightly and glanced away, "but I think we ought to go out for a celebratory drink anyway."

Mac glanced over at Don and smiled slightly. "A celebratory drink it is." He paused. "Do you like jazz?"

***

Don's answer to his question--"Jazz is good"--told Mac that he wasn't a particular fan, but he decided to run with Don's willingness to accept the suggestion and took him to the club where Mac played on Wednesdays, work permitting. He'd never brought anyone there before, not even Claire, since he'd found the place after he'd lost her, but it seemed right to take Don there.

When they stepped up to the door, the man taking cover fees caught Mac's eye and glanced at Don. Mac nodded and the cover was waived for them. Smiling a little in thanks, Mac noticed the guy's curious gaze touching on Don a second time.

"You don't bring people here very often, do you?" Don asked as they stepped deeper into the club.

"You're the first," Mac confirmed. "Danny and Lindsay showed up once, but they didn't come with me."

"Thank you," Don said, touching Mac's elbow briefly.

Mac blinked, and it was only then that he realized exactly  _why_  it had seemed so right to bring Don here. It was a little piece of his life that he could give the other stallion without any reservations. He had no obligations here, no status conflicts, no sensitive history. It was where he went to relax, to just be himself.

Still turning this realization over in his head, Mac said "You're welcome" quietly. As Don smiled in acknowledgment, that persistent, mysterious anxiety eased, and the mystery of it fell apart. He had given himself over to Don, but Don had never exactly staked his claim, which meant Mac would probably take a little longer to find his anchor.

 _There's nothing you can do about it,_  Mac told himself, and there was a certain odd reassurance in that. His instincts would sort themselves out, or Don would sort them out for him. In the meantime...in the meantime there was music to enjoy.

Mac led Don to a table that was a little further from the stage than Mac normally sat when he wasn't playing himself. He didn't come here with people, which meant that he didn't normally need to be able to make conversation.

They'd hardly taken their seats when one of the waitresses came around. "Hey, Mac," she said cheerfully. "Showing your friend the place?" She was asking, of course, because it was Friday and he didn't normally come in outside of Wednesdays.

"Yeah," he answered. "Amanda, meet Don Eppes. Don, Amanda Reese." They nodded at each other, since Amanda was holding her pen and order pad. "We just closed a really old cold case," Mac explained. "Figured a little celebration was in order."

"Hey, congratulations! Drinks on the house, then," she said.

"Manda--" Mac started to protest, but she interrupted, shaking her head.

"Nope, no arguing, mister. I know how you, and presumably your friend," she glanced at Don quickly to include him, "obsess over some of those cases. Relax and enjoy. Now, what can I get you?"

Mac shook his head, but let it go. "A Sam Adams, then," he said.

"The same," Don said when Amanda looked to him for his order.

"Coming right up," she said, smiling and tapping her pen on the pad sharply before heading away from the table.

"I take it you're a regular?" Don asked, smiling.

Mac laughed. "Yeah. Usually on Wednesdays, though, and usually I play a set or two." He tilted his head at the stage in illustration. He only recognized two of the quintet currently playing, since this wasn't his regular night.

Don glanced over his shoulder at the live music and turned back to Mac. "Guitar, right?"

Lindsay had mentioned it, Mac remembered. "Bass guitar," he confirmed.

"Playing is important to you?" Don asked, but it sounded more like a statement than a question.

Mac nodded anyway. "It makes it easier for me to relax, to connect to people."

"I admit, I don't generally have a lot of time for music," Don said. "Charlie works with headphones on all the time, but I can't think with music playing. It makes me want to listen to it."

Mac shrugged. "It's the kind of thing you have to make time for," he said. "But it can give you a lot if you do. Well, it gives me something, at least."

"My mom felt that way about music," Don said, his eyes going a little distant. Amanda returned before he could go on and plunked their bottles down on the table. Don's eyes lost the far away look and he smiled a thank you at her before she left. Then he turned his attention back to Mac. "She played piano," he said. "My mom, that is. I didn't know she played at all until recently, that's how private she kept it."

"How did you find out?" Mac asked curiously. Don's mother, he knew, had passed away almost three years before.

Don turned his bottle around with his fingers for a moment. "Charlie was digging around in the garage for some files he needed and he stumbled across this box of music she'd composed."

"Composing? That sounds a little more serious than a hobby."

"It was," Don confirmed. "Dad says she was very good, but she had to make a choice between composing professionally and her career in law. She chose law, at least partly because the family needed the support, and up until Charlie showed him that music, Dad thought that she had given it up completely."

"It's hard to give something up entirely when it's that much a part of you," Mac said quietly.

"Yeah. Dad felt really bad that he hadn't known what a difficult choice it was for her." Don paused to take a long drink from his beer. "Looking back, it's easy to see that it was important to her. She tried to make Charlie and me learn to play." He smiled ruefully and shook his head. "Neither of us took to it. She must have been really disappointed."

"Sad, maybe," Mac said, "that she couldn't share that with you, but I doubt she was disappointed in you."

Don shook his head. "I loved my mom," he said, "and I did my best to take care of her, but don't know that I'll ever believe that we were close. She and Charlie were the ones that bonded. She even went away to Princeton with him. He was young. He needed her." Don was quiet for a long moment. "I don't know. Maybe that's why I started trying to play again. To feel close to her."

"Started trying?" Mac prompted, curious.

Don nodded. "I remember all the principles, of course, of how to play and how to read music, but the muscle memory isn't there. It comes out sounding stilted."

"That's just practice," Mac said. "It'll come, if you make the time for it."

"I'd probably work more at it if the piano wasn't in Dad's--Charlie's--place," Don admitted. "I feel self-conscious playing where I know they can hear me."

"If you really want to try," Mac said, a little diffidently, "you can rent a piano. Or buy a keyboard. Some of them come relatively cheap, especially since you probably won't need the full 88 keys. Not unless her compositions are quite advanced."

"Or I could just suck it up and play at Charlie's place," Don said wryly.

Mac shrugged. "You want to enjoy it. I don't think having to suck it up should be a part of the experience."

"What's your favorite part of playing?" Don asked.

"Playing with others," Mac said immediately. "I love hearing the threads of the music come together. Of course, the bass guitar isn't a very good instrument to play solo regardless, but I think that's part of why I like it. The bass line is what grounds the rest of the music. It's the foundation that lets the other instruments play."

Don smiled slightly. "I think you probably make a very good foundation."

Mac met Don's eyes and smiled broadly.

"I mean it," Don said, apparently taking Mac's pleasure for disbelief. "That's a big part of what you do at work, too. You build the foundation that the rest of the case has to rest on. You're very good at that."

"My subordinates might not agree with you," Mac said wryly.

Don waved that off. "Being a boss is different area entirely."

And he wasn't very good at it, Mac knew, although he didn't say so aloud. Instead he let Don turn the conversation to other topics and let himself sit back and relax and drink his beer. They weren't drinking fast, but Amanda kept them supplied and the time slipped away. Mac was surprised when he looked up to find her standing over their table, looking regretful. "Sorry, guys," she said, "but we've got to close."

Mac glanced at his watch in surprise. It was 2:00am. "Sorry, Manda," he said. "I completely lost track of time."

"No problem," she said, tired now but still smiling.

They let her shepherd them out the door and paused there for a moment. Mac had parked his car a couple of blocks away, so they headed towards it. In almost three hours they'd only had six beers between the two of them, so he was confident they were good to drive. But Mac found himself chuckling at the story Don had begun, watching his eyes crinkle with laughter, and not caring when they passed the car and kept going.

It was a nice night.

***

It was past four in the morning by the time Mac and Don finally drifted back to Don's hotel. Mac automatically followed him up to his room as the conversation wound down. Finally, standing outside Don's hotel room, Mac had to admit the night was over. "I guess this is good night," he said, hearing a shade of reluctance in his own voice. As if that wasn't evident from the fact that he'd kept the conversation up until four in the morning.

"Yeah," Don said. He held his card key in his hands but didn't open the door yet.

 _Maybe he'll invite me in._  Almost as soon as the thought occurred, Mac mentally shook his head at himself. It was already so late it was early. Don had to sleep. But...he hadn't opened his door yet, or said good night.

Don spoke. "I have to be up in less than four hours." His tone was almost apologetic. Mac couldn't help feeling a wash of disappointment. "It was really good to meet you in person, Mac," Don said softly.

"Likewise," Mac said, managing a smile. "Can I drive you to the airport in the morning?"

"Yeah," Don said. "Yeah, that'd be good."

"I'll be by around 7:00am, then," Mac said. He started to step away from the room, then hesitated.  _Don't be stupid. The man is going back to L.A. in a couple of hours._  "Good night, Don."

Don nodded, but when Mac moved to leave, a hand on his arm stopped him. "Mac," Don said. "If you're going to drive me to the airport at 7:00, you'll hardly be home before you have to turn around and come back. Stay here. You can catch a couple of hours of sleep."

He wanted to. God, he could hardly believe how much he wanted to. But Mac couldn't make himself say yes.

"Mac," Don said again, firmly. He opened the door to his room. "Come in."

He went.

Once he'd crossed the threshold and Don had let the door fall closed it seemed easier. Don's scent floated through the room, lingering on sheets and discarded clothing and hanging in the air, since the windows didn't open. It was his space as much as a hotel room could be and Mac...belonged.

After a moment's hesitation Mac sat down on the end of the bed and tried to figure out where to go from here. God, he was tired. Don gave him a small smile as he stepped into the bathroom to get ready to sleep. Mac rubbed a hand over aching eyes. Sleep. Sleep would be good. He didn't have a toothbrush or anything here, though. Was there anything in his car? Did he really want to go all the way down to his car?

"Hey." Mac looked up and was surprised to find Don standing over him in a t-shirt and boxers. "You look like I feel," Don said, smiling a little. "You don't have to sleep in your suit jacket, you know."

Mac blinked and shrugged out of the jacket. "I'm not thinking too clearly, I think."

"That's okay, we're done with thinking clearly. Go ahead and scoot up on the bed."

Mac obeyed, lying down because it felt strange to sit up with his legs stretched out in front of him. He felt a tug on his foot and managed to lift his head again. "Hmm?"

"Just taking off your shoes," Don said softly. "Relax. I've got you."

 _I've got you._  Mac felt like he was going to melt into the bedspread. He knew he should get under it, but he was tired, and his nerves felt worn, and he could feel Don's hands on his feet, which ached half the time these days... He slept.

***

Don pulled the zipper shut on his suitcase and stood there for a moment, staring at it. Three days had gone by remarkably fast, but at the same time he felt like he'd been in New York for ages. Leaving felt vaguely wrong, as if he'd put down roots and now had to tear them up again.

 _You_ did _put down roots,_  Don thought. He turned and sat heavily on the queen size bed next to his suitcase, listening to the sound of the shower running.  _You added a new member to your herd and now you're leaving him behind. Of_ course _it feels wrong._

Leaning forward, Don braced his arms on his thighs and, bowing his head, reached up to rub the back of his neck with one hand. Maybe he shouldn't have accepted Mac beyond the three days he'd known he'd be spending in New York, but to be honest, once the offer had been made the idea of limiting it hadn't occurred to him beyond the need to confirm that it wasn't what Mac wanted.

If he'd just taken a minute to think about the consequences...  _I'd probably have done it anyway,_  Don acknowledged wryly. He'd never been able to resist taking a new person under his wing; he enjoyed surrounding himself with his people. Add on to that the fact that it was Mac, whom he'd been advising and drawing upon for months, and that Mac was a centaur and would therefore  _understand_ , and that Mac was a  _stallion_ , someone potentially just as powerful as Don and yet totally willing to hand over control... Don knew better than to think he could have turned all that down.

The shower shut off and Don went to the room service tray he'd arranged before he'd joined Mac in sleep the night before and poured some coffee. Mac exited the bathroom a couple of minutes later, looking more than a little rumpled after putting the clothes he'd slept in back on.

"Morning," Mac acknowledged.

"Morning." Don held out a coffee mug.

"Thank you," Mac said fervently, and took a long sip.

"Three hours wasn't nearly enough sleep," Don said wryly, breathing in the fumes of his own coffee.

The two of them picked at a variety of muffins and fruit and guzzled coffee for a few minutes before Don glanced at the clock and had to concede defeat. "We have to head out," he said reluctantly.

Mac just nodded and stood. "You want a hand with anything?"

"Nah, I'm good," Don said. He drained his last cup of coffee and set it aside, then shrugged into his jacket and grabbed his wheeled carry on and his briefcase. He glanced around the room to see if he'd missed anything and found himself wondering if it was really time to leave. _Your whole life is back in L.A.,_  Don reminded himself.

 _Not quite your whole life._

"You okay to drive?" he asked aloud. "You were pretty out of it last night."

"I'm thoroughly caffeinated," Mac said wryly. "I think I can get us there in one piece."

They kept up the small talk as they loaded up the car and headed for the airport, neither of them mentioning their destination. Don wondered if the thought of what would happen between them over the next days or weeks was looming as large in Mac's mind as it was in his own. Had a herd stallion ever lived so far from one of his people before? Don didn't know. He couldn't imagine one had, if it felt like this.

But finally they stood outside the security checkpoint and there was no ignoring it anymore. They were silent for a long moment before Mac said, quietly, "You have to go."

 _You have to stay,_  Don thought, but it sounded too much like a question in his head, so he didn't voice it. Of course Mac had to stay. Don's whole life was in L.A., but Mac's whole life was here in New York.  _He's yours. He belongs with you._  Don forced the thought to the back of his mind. For God's sake, they'd only met three days ago. Even if they had known each other for eight months.

"Yeah," Don said, and his voice sounded a little rougher than the obvious circumstances really warranted. He almost said,  _I'll call,_  but it sounded too much like the end of an unsuccessful date, so he bit those words back, too.

"If you ever need anything," Mac said awkwardly.

Don managed to smile a little at that. "You're at my service," he said.

Mac didn't exactly smile, but his expression lightened. "Yeah."

Don hesitated, then turned and walked away without saying goodbye. On the other side of the checkpoint, just before he would pass out of view, he turned and looked back. Mac was still standing there, watching.

Waiting, maybe.

Don caught Mac's eye for a moment and smiled before turning for the last time and going to meet his flight.


End file.
